French Onion Green Bean Casserole
A from-scratch, no canned soup green bean casserole with cozy French onion flavor. An elevated Thanksgiving side dish that still feels classic, and it’s perfect for make-ahead prep.
By @wellplated
Cook time: 60 minutes
Servings: 6
Ingredients
- 4 medium yellow onions
- 2.5 lbs green beans
- 8 oz baby bella mushrooms
- 5 T unsalted butter
- 2 T all-purpose flour
- 2.5 c milk
- 1.5 c shredded Gruyère cheese
- 1 c croutons
- 0.25 c freshly grated Parmesan cheese
Instructions
- Caramelize the thinly sliced yellow onions.
- Blanch the trimmed and cut green beans.
- Sauté the sliced baby bella mushrooms in butter.
- Stir in all-purpose flour and milk to the sautéed mushrooms to make a creamy mushroom sauce.
- Layer the blanched green beans, creamy mushroom sauce, caramelized onions, and shredded Gruyère in a casserole dish.
- Top the layered casserole with a mixture of lightly crushed croutons and freshly grated Parmesan cheese, and more Gruyère.
- Bake the casserole at 375°F until hot and bubbly.