Broccoli & Cremini Mushroom Casserole in Bechamel Sauce

8 servings Prep: 20 m Cook: 55 m Total: 1 h 15 m Intermediate
Broccoli & Cremini Mushroom Casserole in Bechamel Sauce
This is my own variation on a broccoli casserole that is all scratch—made with fresh broccoli, cremini mushrooms, homemade bechamel sauce, and two kinds of cheese. I fix this for holiday meals and special occasions.

Ingredients

  • 5 tbsp butter
  • 4 tbsp all-purpose flour
  • 4 cups milk
  • 2 tsp salt
  • 1/4 tsp freshly grated nutmeg
  • 2 heads fresh broccoli, cut into florets
  • 8 ounces fresh cremini mushrooms, quartered into wedges
  • 2 cups Monterrey Jack, grated
  • 1 cup sharp cheddar, grated
  • 1 cup panko bread crumbs for topping (optional)

Step-by-Step Instructions

  1. Mix sharp cheddar and Monterrey Jack cheese. Bechamel Sauce: In a medium saucepan, heat the butter over medium-low heat until melted. Add the flour and stir until smooth. Over medium heat, cook until the mixture turns a light, golden sandy color, about 6 to 7 minutes. Meanwhile, heat the milk in a separate pan until just about to boil. Add the hot milk to the butter mixture 1 cup at a time, whisking continuously until very smooth. Bring to a boil. Cook 10 minutes, stirring constantly, then remove from heat. Season with salt and nutmeg, and set aside until ready to use.
  2. Broccoli-Cremini Mushrooms: Steam vegetable mixture in steamer for eight minutes. Mix 1/2 of the cheese mixture into Bechamel Sauce. Blend with steamed vegetables. Pour into casserole dish.
  3. Cover with remaining cheese mixture. Optional: top with 1 cup of panko bread crumbs. Bake at 350 degrees for 30 minutes.

Common Problems and Solutions

Q: Why is my bechamel sauce lumpy?

A: Make sure to whisk continuously when adding the hot milk to the roux, and add it gradually one cup at a time. If lumps form, strain the sauce through a fine-mesh sieve.

Q: Can I make this ahead?

A: Yes, assemble the casserole up to the point of baking, cover tightly, and refrigerate for up to 24 hours. Add 10-15 minutes to the baking time if going straight from the refrigerator to the oven.

Q: My sauce is too thick or too thin—what went wrong?

A: For a thicker sauce, cook it a bit longer while stirring. For a thinner sauce, whisk in a little more warm milk. The sauce will thicken slightly as it bakes, so aim for a consistency that coats the back of a spoon.

Tips and Techniques

Don’t skip heating the milk before adding it to the roux—cold milk will cause the roux to seize and create lumps. Fresh nutmeg makes a big difference in bechamel sauce compared to pre-ground.

Ingredient Substitutions

  • cremini mushrooms: white button mushrooms or sliced portobello
  • panko bread crumbs: regular bread crumbs or crushed Ritz crackers
  • Monterrey Jack cheese: mozzarella or Colby Jack

Equipment Needed

  • Medium saucepan for bechamel sauce
  • Whisk
  • Vegetable steamer
  • 9x13 inch casserole dish