Name: Grandma’s Onion Squares Recipe
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Cuisine: American
Ingredients: 1 sheet refrigerated crescent roll dough; 2 tablespoons unsalted butter; 2 large yellow onions, thinly sliced; 1/2 teaspoon salt; 1/4 teaspoon black pepper; 1/2 teaspoon dried thyme; 1 cup shredded Swiss cheese; 1/4 cup mayonnaise; 1 large egg, beaten; 1 tablespoon all-purpose flour

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If you’re searching for that one dish that always disappears first at gatherings, look no further than Grandma’s Onion Squares. This beloved recipe transforms humble onions into a savory, cheesy, golden-baked treat with a flaky crescent crust that’s impossible to resist. Every bite brings back cozy kitchen memories and family get-togethers, making it a must-have for potlucks, holiday tables, or cozy afternoons when you crave something truly comforting. Grandma’s Onion Squares are proof that simple ingredients can create unforgettable flavor.

Grandma’s Onion Squares Recipe - Recipe Image

Ingredients You’ll Need

What makes Grandma’s Onion Squares so special is their simplicity: every ingredient has a job, and together they create magic. Here’s what you’ll need, with each item playing a unique role in taste, texture, or that glorious golden color.

Refrigerated crescent roll dough: The flaky, buttery base that makes these squares so easy and delicious; press it firmly for a seamless crust.
Unsalted butter: Essential for sautéing onions to tender, caramelized perfection; don’t rush this step!
Yellow onions: Thinly sliced, they’re the star of the show; their sweetness intensifies as they cook down.
Salt: Just enough to bring out the natural savoriness of the onions without overpowering the dish.
Black pepper: Adds a gentle hint of warmth and depth to balance the sweetness of the onions.
Dried thyme: This aromatic herb gives the onions a subtle earthiness that feels oh-so-cozy.
Shredded Swiss cheese: Melts into a creamy, nutty layer that binds the onion filling together.
Mayonnaise: Keeps the filling moist and rich, ensuring every bite is luscious and flavorful.
Large egg: Acts as a binder to hold the filling together, giving it that perfect sliceable texture.
All-purpose flour: Adds just enough structure so the filling sets up beautifully without being dense.

How to Make Grandma’s Onion Squares

Step 1: Prepare the Baking Dish and Dough

Start by preheating your oven to 375°F (190°C) and lightly greasing a 9×9-inch baking dish. Unroll the refrigerated crescent roll dough and press it into the bottom of your dish, carefully pinching and sealing the seams so you have a flat, even crust. This simple step creates the flaky, golden base that makes Grandma’s Onion Squares so irresistible.

Step 2: Caramelize the Onions

Melt the butter in a large skillet over medium heat. Add the thinly sliced onions, then sprinkle in the salt, black pepper, and thyme. Take your time sautéing the onions for 15 to 20 minutes, stirring occasionally. You’ll know they’re ready when they turn soft, golden, and beautifully aromatic. This slow caramelization is where the magic happens, so don’t rush it—the flavor payoff is worth it!

Step 3: Mix the Filling

While the onions cool slightly, grab a bowl and combine the shredded Swiss cheese, mayonnaise, beaten egg, and flour. Stir until the mixture is smooth and creamy. Fold in the warm, caramelized onions, making sure everything is well coated and evenly distributed. This luscious filling is the heart of Grandma’s Onion Squares, combining rich cheese and sweet onions in every bite.

Step 4: Assemble and Bake

Spoon the onion-cheese mixture over the crescent dough, spreading it into an even layer. Pop the dish into your preheated oven and bake for 20 to 25 minutes, or until the top is beautifully golden and the center is set. You’ll know it’s done when the kitchen smells amazing and the top has a little color. Let the squares cool for a few minutes before slicing—this helps them hold together perfectly.

How to Serve Grandma’s Onion Squares

Garnishes

To make your Grandma’s Onion Squares extra special, sprinkle them with a dusting of fresh chopped parsley or a pinch of extra thyme right before serving. A quick grind of black pepper adds a bit of visual flair and a pop of flavor. These little touches not only make them look gorgeous but also add freshness and aroma.

Side Dishes

These savory squares are versatile enough to be the star of your appetizer spread or a tasty side for soups and salads. Pair Grandma’s Onion Squares with a crisp green salad, a bowl of tomato soup, or alongside charcuterie for a well-rounded feast. They also shine next to roasted vegetables or as part of a brunch buffet.

Creative Ways to Present

For parties, cut Grandma’s Onion Squares into bite-sized pieces and serve them on a platter with cocktail picks. Stack them on a rustic wooden board for a charming touch, or tuck them into lunchboxes for a flavorful surprise. If you’re feeling fancy, serve with a dollop of sour cream or a swipe of grainy mustard on the side for dipping.

Make Ahead and Storage

Storing Leftovers

Leftover Grandma’s Onion Squares store beautifully, making them just as irresistible the next day. Place any cooled squares in an airtight container and refrigerate for up to three days. The flavors meld and deepen, making leftovers a real treat for quick lunches or snacks.

Freezing

If you’d like to make a batch ahead or save extras, Grandma’s Onion Squares freeze wonderfully. Once fully cooled, arrange the squares in a single layer on a baking sheet to freeze, then transfer to a freezer bag or container. They’ll keep their texture and flavor for up to two months—just be sure to label the container so you remember the deliciousness waiting inside!

Reheating

For best results, reheat Grandma’s Onion Squares in a 325°F oven until warmed through, about 10 minutes. This keeps the crust crisp and the filling creamy. If you’re in a hurry, a quick zap in the microwave will work, but the oven method preserves that fresh-baked texture everyone loves.

FAQs

Can I use a different type Appetizer

Absolutely! While Swiss is classic for Grandma’s Onion Squares, Gruyère or a sharp white cheddar both make delicious substitutes. Each cheese brings its own personality and meltiness, so feel free to experiment based on your tastes or what you have on hand.

Can I make Grandma’s Onion Squares ahead of time?

Yes, you can prepare them up to a day in advance. Bake, cool, and refrigerate the squares, then reheat before serving. This makes entertaining a breeze—just warm them up and enjoy!

Do I need to use crescent roll dough, or can I substitute another base?

Crescent roll dough gives that signature flaky crust, but you can use puff pastry or even homemade pie dough if you prefer. Just make sure to adjust baking times as needed, since different doughs cook at different rates.

Can I add other ingredients to the filling?

Definitely! A handful of sautéed mushrooms, a pinch of red pepper flakes, or a sprinkle of crispy bacon bits all complement the onion and cheese flavors. Just be careful not to overload the filling so the squares hold together nicely.

Are Grandma’s Onion Squares suitable for vegetarians?

Yes, they’re a vegetarian-friendly appetizer, as long as the cheese and crescent dough you use are free from animal rennet. Always check labels if you’re cooking for strict vegetarians.

Final Thoughts

There’s something truly special about sharing recipes that have stood the test of time, and Grandma’s Onion Squares are exactly that kind of dish. Whether you’re making them for a party, a cozy family night, or just to treat yourself, you’ll fall in love with their comforting flavors and easy preparation. Give them a try and watch how quickly they become a favorite at your table!

Grandma’s Onion Squares Recipe

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4.6 from 16 reviews

Author: admin
Total Time: 40 minutes
Yield: 9 squares 1x
Diet: Vegetarian

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Description

Grandma’s Onion Squares are a deliciously savory appetizer featuring caramelized onions, creamy Swiss cheese, and flaky crescent roll dough baked to golden perfection. Perfect for potlucks or casual gatherings, these squares offer a flavorful and easy-to-make treat that can be enjoyed warm or at room temperature.

Ingredients

Scale

For the Dough

1 sheet refrigerated crescent roll dough
2 tablespoons unsalted butter

For the Onion Mixture

2 large yellow onions, thinly sliced
1/2 teaspoon salt
1/4 teaspoon black pepper
1/2 teaspoon dried thyme

For the Cheese Mixture

1 cup shredded Swiss cheese
1/4 cup mayonnaise
1 large egg, beaten
1 tablespoon all-purpose flour

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Instructions

Prepare the oven and dish: Preheat the oven to 375°F (190°C) and lightly grease a 9×9-inch baking dish to prevent sticking.
Form the crust: Unroll the crescent roll dough and press it firmly into the bottom of the baking dish, making sure to seal any seams so the dough forms a flat and uniform crust.
Sauté the onions: In a large skillet, melt the unsalted butter over medium heat. Add the thinly sliced onions, salt, black pepper, and dried thyme. Cook for 15–20 minutes, stirring occasionally, until the onions become soft, golden brown, and caramelized.
Mix the cheese filling: In a separate bowl, combine the shredded Swiss cheese, mayonnaise, beaten egg, and all-purpose flour. Stir until the mixture is well blended.
Combine onions and cheese mixture: Fold the sautéed onions into the cheese mixture, ensuring they are evenly incorporated.
Assemble the squares: Spread the onion and cheese mixture evenly over the crescent roll dough crust in the dish.
Bake: Place the baking dish in the oven and bake for 20–25 minutes or until the top is golden brown and set.
Cool and serve: Allow the onion squares to cool slightly before cutting into 9 even squares and serving warm or at room temperature.

Notes

These onion squares are delicious both warm and at room temperature, making them perfect for parties and potlucks.
For a flavor variation, substitute Swiss cheese with Gruyère or cheddar cheese.
Ensure onions are caramelized properly to deepen the flavor and sweetness of the dish.
You can prepare the onion mixture a day ahead and assemble before baking to save time.

Prep Time: 15 minutes
Cook Time: 25 minutes
Category: Appetizer
Method: Baking
Cuisine: American