Do I need canned soup for French Onion Hashbrown Casserole?

No. You’ll build flavor with slow-cooked onions and a brief beef-broth reduction, then bind thawed, dry hashbrowns with eggs and dairy for a cheesy hashbrown casserole (no canned soup).

What cheese is best for “French onion” flavor?

Gruyère brings nutty depth and body; a little Swiss or low-moisture mozzarella adds gentle stretch. Finish with parmesan for a bronzed top on your gruyere hashbrown casserole.

Can I use fresh potatoes instead of frozen hashbrowns?

Yes. Shred russets, rinse, and squeeze bone-dry in a towel. Measure about 32 oz by weight. Dryness is key to prevent soggy pockets in a caramelized onion hashbrown casserole.

How do I keep the casserole from getting watery?

Thaw and pat hashbrowns very dry, caramelize onions fully (reduce with broth until syrupy), and bake covered first, then uncovered to brown. Rest 10–15 minutes so slices hold.

Absolutely. Assemble and refrigerate up to 24 hours, then bake (add 5–10 minutes covered). Or par-bake, chill, and finish day-of for a make-ahead breakfast casserole that tastes freshly baked.

Yes. Freeze unbaked for the best texture (thaw overnight, add time covered), or freeze baked squares and reheat at 325°F. Either way, your baked hashbrown casserole with onions will re-crisp on top.

How To Make Delicious French Onion Hashbrown Casserole

Description

French Onion Hashbrown Casserole turns jammy caramelized onions, nutty Gruyère, and a creamy hashbrown base into a sliceable, bubbly bake with crisp corners. No canned soup—just real onion depth, a light broth reduction, and a smart cheese blend that melts clean and reheats beautifully for brunch or dinner.

Ingredients

Scale

32 oz frozen shredded hashbrowns, thawed and patted very dry
3 large yellow onions (about 2 lb), thinly sliced
3 Tbsp unsalted butter (for onions), plus 1 Tbsp to grease dish
1 Tbsp olive oil
½ cup beef broth (or 1 tsp beef base + water), reduced with onions
2 cups shredded Gruyère (packed)
1 cup shredded Swiss or low-moisture mozzarella
1 cup sour cream (or full-fat Greek yogurt)
3 large eggs
1–2 tsp fresh thyme leaves (or ½ tsp dried)
¾–1 tsp kosher salt, plus more to taste
½ tsp black pepper
2–3 Tbsp grated parmesan (optional, for bronzed top)

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Instructions

Caramelize onions: Add 3 Tbsp butter and 1 Tbsp oil to a wide skillet over medium-low. Stir in onions and a good pinch of salt. Cook 25–35 minutes, stirring often, until deep golden and jammy.
Reduce: Add ½ cup beef broth and simmer until syrupy and mostly absorbed. Take off heat and cool 5 minutes.
Heat oven: Set to 375°F. Butter a 9×13-inch (3-qt) baking dish.
Mix custard: In a large bowl, whisk eggs, sour cream (or yogurt), thyme, ¾–1 tsp salt, and pepper until smooth.
Fold base: Add very dry hashbrowns, half the caramelized onions, and half the Gruyère + Swiss. Fold until evenly coated.
Layer: Spread base in the dish. Scatter remaining onions over the top, then the remaining cheeses. Finish with parmesan if using.
Bake covered: Cover tightly with foil and bake 25 minutes to steam-set the center.
Uncover to brown: Remove foil and bake 18–22 minutes until the top is bubbling and golden with crisp corners.
Optional color: For deeper bronze, broil 1–2 minutes, watching closely.
Rest & serve: Cool 10–15 minutes for clean slices. Cut into squares and serve hot.

Notes

Dry the hashbrowns well: Spread on towels 10–15 minutes so the casserole stays custardy, not watery.
Cheese strategy: Fold half into the base for creaminess; keep half for the bubbly lid.
Smart swaps: Use robust vegetable broth for a vegetarian version; Greek yogurt replaces sour cream 1:1; if no Gruyère, use 1½ cups Swiss plus ½ cup parmesan for nutty depth.

Prep Time: 20 minutes
Cook Time: 1 hour
Category: Side Dish, Brunch
Method: Baked
Cuisine: American

Nutrition

Serving Size: 1 square (about 1/12 pan)
Calories: 360 kcal
Sugar: 5 g
Sodium: 620 mg
Fat: 20 g
Carbohydrates: 28 g
Fiber: 2 g
Protein: 15 g
Cholesterol: 110 mg