Description
A rich, creamy, and cheesy casserole featuring caramelized onions, tender broccoli, and a Gruyère cheese sauce, topped with buttery panko breadcrumbs. Perfect for holidays, potlucks, or cozy family dinners.
Ingredients
Scale
- 1 tbsp olive oil
- 6 tbsp unsalted butter, divided
- 2 large yellow onions, thinly sliced
- ½ tsp granulated sugar
- 1 tsp kosher salt, divided
- 4 cups broccoli florets, blanched and well-drained
- 2 tbsp all-purpose flour
- 1 cup low-sodium beef broth (or vegetable broth for vegetarian)
- 1 cup whole milk
- 6 oz Gruyère cheese, shredded
- 1 cup sharp cheddar cheese, shredded, divided
- 2 garlic cloves, minced
- ½ tsp dried thyme
- ½ tsp ground black pepper
- 1 cup panko breadcrumbs
- 2 tbsp melted butter
- Optional: fresh parsley (for garnish)
Instructions
- Preheat oven to 375°F (190°C). Grease a 9×13″ baking dish.
- Heat olive oil and 2 tbsp butter in a skillet over medium-low. Add onions, sugar, and ½ tsp salt. Cook 20–25 minutes, stirring, until caramelized. Add garlic and thyme; cook 1 minute. Set aside.
- Blanch broccoli in boiling salted water for 2 minutes. Drain and pat dry.
- In a saucepan, melt 2 tbsp butter over medium heat. Whisk in flour and cook 1 minute. Gradually whisk in broth and milk. Simmer 3–4 minutes until thickened.
- Remove from heat. Stir in Gruyère and ½ cup cheddar until melted. Season with remaining salt and pepper.
- In baking dish, combine broccoli, caramelized onions, and cheese sauce. Top with remaining cheddar.
- Toss panko with melted butter (and parsley, if using). Sprinkle over top.
- Bake 18–22 minutes until bubbly and golden. Rest 5–10 minutes before serving.
Notes
- Use freshly grated cheese for best melting.
- Drain broccoli well to prevent watery texture.
- Can be made vegetarian or gluten-free with substitutions.
- Assemble up to 1 day ahead without topping, refrigerate, then bake when ready.
- Prep Time: 20 minutes
- Cook Time: 30 minutes
- Category: Side Dish
- Method: Baking, Caramelizing
- Cuisine: American
Nutrition
- Serving Size: 1/6 of casserole
- Calories: 320
- Sugar: 6g
- Sodium: 420mg
- Fat: 22g
- Saturated Fat: 13g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 17g
- Fiber: 2g
- Protein: 12g
- Cholesterol: 60mg