Creamy Broccoli, Potato & Mushroom Casserole with Garlic-Herb Sauce

This comforting casserole combines tender vegetables with a rich, cheesy sauce, creating a perfect vegetarian main dish. Drawing inspiration from classic European gratins, this recipe elevates everyday vegetables into a memorable meal.

Time Requirements

• Prep Time: 30 minutes
• Cooking Time: 35 minutes
• Total Time: 1 hour 5 minutes
• Servings: 6-8

Ingredients

For the Vegetables

• 1 large head broccoli (about 500g), cut into florets
• 500g (17.6 oz) waxy potatoes, cubed
• 8-10 medium mushrooms (250g), sliced
• 1 yellow bell pepper, diced
• 2 cloves garlic, minced
• 2 bay leaves
• 6-8 whole black peppercorns
• 2 tablespoons (30ml) olive oil
• 1 teaspoon sea salt, divided

For the Cheese Sauce

• 2 tablespoons (30g) unsalted butter
• 50g (2 tablespoons) all-purpose flour
• 500ml (2 cups) whole milk
• 40g (1.4 oz) Parmesan cheese, freshly grated
• 200g (7 oz) mozzarella cheese, grated
• ½ teaspoon freshly grated nutmeg
• 1 teaspoon sea salt
• ½ teaspoon black pepper

For the Garlic-Herb Sauce

• 1 tablespoon Greek yogurt or sour cream
• 1 tablespoon mayonnaise
• 1 clove garlic, finely minced
• 2 tablespoons fresh dill, chopped
• Pinch of salt and pepper

Instructions

Preparing the Vegetables

1. Bring large pot of salted water to boil.
2. Blanch broccoli florets for 2 minutes.
3. Transfer to ice bath immediately.
4. In same water, add potatoes, bay leaves, peppercorns.
5. Boil for 7 minutes until partially cooked.
6. Drain and remove bay leaves and peppercorns.

Cooking the Mushrooms

1. Heat olive oil in large skillet over medium-high heat.
2. Add mushrooms in single layer.
3. Cook without stirring for 3-4 minutes until golden.
4. Add diced yellow pepper, cook 2 minutes.
5. Add minced garlic, cook 1 minute.
6. Season with salt and pepper.
7. Remove from heat.

Making the Cheese Sauce

1. Melt butter in medium saucepan over medium heat.
2. Add flour, whisk constantly for 1-2 minutes.
3. Gradually add milk, whisking continuously.
4. Cook until thickened, about 5 minutes.
5. Add Parmesan cheese, stir until melted.
6. Season with nutmeg, salt, and pepper.

Assembly

1. Preheat oven to 180°C (350°F).
2. Grease 9×13 inch baking dish.
3. Layer blanched broccoli on bottom.
4. Add par-cooked potatoes.
5. Spread mushroom mixture evenly.
6. Pour cheese sauce over vegetables.
7. Top with grated mozzarella.

Baking

1. Bake uncovered for 35 minutes.
2. If needed, broil 2-3 minutes for golden top.
3. Let rest 10 minutes before serving.

Preparing Garlic-Herb Sauce

1. Mix Greek yogurt/sour cream with mayonnaise.
2. Stir in minced garlic.
3. Add chopped dill.
4. Season with salt and pepper.
5. Chill until serving.

Storage and Reheating

• Store covered in refrigerator up to 3 days
• Reheat in 350°F (175°C) oven for 15-20 minutes
• Store sauce separately up to 2 days
• Not recommended for freezing

Recipe Variations

• Add cauliflower florets
• Use different cheese combinations
• Include sautéed onions
• Add breadcrumb topping
• Include herbs like thyme or rosemary

Nutrition Information

Per Serving (1/6 of recipe):

• Calories: 380
• Protein: 16g
• Carbohydrates: 35g
• Fiber: 5g
• Fat: 22g
• Saturated Fat: 11g
• Cholesterol: 45mg
• Sodium: 780mg
• Calcium: 35% DV
• Vitamin C: 120% DV

Chef’s Tips

• Use waxy potatoes that hold their shape
• Don’t overcook vegetables in preparation steps
• Make sauce slightly thinner than desired
• Let casserole rest before serving
• Use room temperature milk for smooth sauce
• Grate cheese fresh for best melting
• Season each layer adequately

This vegetable-rich casserole makes a satisfying main course or impressive side dish. The combination of different textures and the rich cheese sauce creates a crowd-pleasing meal that’s perfect for family dinners or potlucks. The additional garlic-herb sauce adds a fresh, tangy element that complements the rich casserole perfectly.