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Broccoli Cauliflower Casserole is the kind of cheesy comfort food I turn to whenever I need to fill a holiday table or dress up a weeknight dinner. Creamy cheese sauce, melting sharp cheddar, golden crispy crumbs on top—every bite is hearty and satisfying, but you still get plenty of fresh veggies in every forkful. I love that you can make it ahead so you are never stuck in the kitchen when guests arrive.
I first made this casserole for my grandmother’s birthday when I needed a veggie side that felt special but did not keep me stuck cooking during the party. The cheesy top won everyone over and now it is my most requested bring along.
Ingredients
- Broccoli: look for tight bright green crowns and fresh stems for the freshest taste
- Cauliflower: find heads that are creamy white with no brown spots for best texture
- Butter: adds richness to both the sauce and the golden crumb topping use a high quality unsalted stick
- Onion: sautéed to sweetness forms the base of the sauce go for a medium yellow onion with firm skin
- Garlic: fresh cloves give a deeper savory flavor chop just before cooking for best result
- All purpose flour: helps the sauce thicken smoothly look for unbleached flour for wholesome flavor
- Milk: whole or two percent blends to make a creamy sauce use milk that is freshest not ultra pasteurized
- Chicken broth: lightens the sauce slightly choose a low sodium version so you can control the flavor
- Fresh thyme: gives a clean herbal lift use leaves stripped from the stems and avoid any wilted bits
- Salt and black pepper: round out the flavor
- Sharp cheddar cheese: bold cheesy bite for perfect melting shred it yourself for the most melt and flavor
- Parmesan cheese: adds nutty saltiness in the topping and sauce grate fresh for the best aroma
- Plain bread crumbs: classic crispy topping use unseasoned and check crispness
- Garlic powder: infuses the crumb topping with flavor a little goes a long way
- Melted butter: binds the topping and enhances browning unsalted is best
Step-by-Step Instructions
- Prep and Blanch the Vegetables:
- Bring a large pot of water to a boil then add broccoli and cauliflower pieces Cook for just four to five minutes until they are bright colored and semi tender Immediately drain and transfer to a lightly greased baking dish This keeps the vegetables vibrant not soggy
- Make the Cheese Sauce:
- In a skillet melt butter over medium heat and add the diced onion and minced garlic Let them cook gently for about four to five minutes You want everything soft and fragrant but not browned Sprinkle in flour while whisking constantly The flour should form a smooth paste with the butter Slowly pour in the milk and chicken broth in a steady stream whisking to keep the sauce lump free Let it bubble and thicken for a few minutes Season with salt pepper and fresh thyme This is where you develop that creamy backbone every bite needs
- Assemble the Casserole:
- Pour the hot cheese sauce evenly over your broccoli and cauliflower in the pan Top with shredded sharp cheddar and parmesan cheeses Spread them gently so every part gets the cheesy goodness
- Make the Crumb Topping:
- In a small bowl combine bread crumbs garlic powder and melted butter Mix until all crumbs are moistened You want a texture like damp sand for easy spreading without clumping
- Top and Bake:
- Scatter the crumb mixture evenly across the top of the casserole Place the dish into the preheated oven and bake for fifteen to twenty minutes The top should turn golden brown and the casserole should be hot and bubbling around the edges Remove from the oven and let sit a couple minutes before serving
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Whenever I make this recipe I get the most excited about roasting fresh broccoli and cauliflower I love seeing their colors deepen in the oven My daughter always sneaks a crunchy crumb topping before dinner even begins and that always makes me laugh
Storage Tips
Let the casserole cool completely before covering and refrigerating Leftovers stay moist for up to three days If you want to freeze it wrap the whole baking pan in plastic wrap and foil A quick bake from frozen will make it taste freshly made
Ingredient Substitutions
You can swap cheddar for mozzarella or Monterey jack for a milder taste For more flavor use a mixture of gruyere and sharp cheddar If you need it vegetarian use low sodium vegetable broth instead of chicken Avoid preshredded cheese for smoothest melting
Serving Suggestions
This casserole goes with just about anything You can serve it with roast chicken or pan seared pork For a vegetarian main pair it with lentil loaf or mushroom steaks At potlucks this dish disappears fast beside turkey and mashed potatoes
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Cultural Context
Hearty vegetable casseroles like this one are a staple at American holiday tables especially Thanksgiving and Christmas The golden crumb topping is a classic home cook trick for stretching a small amount of cheese into a crowd pleasing side I picked up the cheese sauce technique from my aunt who never wrote down a recipe but always taught by example
Recipe FAQs
- → Can I use frozen broccoli and cauliflower?
Yes, frozen vegetables may be used. Just thaw and drain them well to avoid excess moisture in the dish.
- → What cheeses work best in this dish?
Sharp cheddar provides bold flavor, while parmesan adds nutty richness. Other melting cheeses like Gruyère or Monterey Jack can be added for variation.
- → Can this be prepared ahead of time?
Absolutely. Assemble up to two days in advance, cover, and refrigerate. Bake before serving for best texture.
- → How do I make the topping extra crispy?
Ensure breadcrumbs are well coated in melted butter before adding to the casserole. Bake uncovered until golden and crisp.
- → Is it possible to make this vegetarian?
Simply substitute vegetable broth for chicken broth to keep the dish fully vegetarian without sacrificing flavor.
- → Can gluten-free flour and breadcrumbs be used?
Yes, gluten-free alternatives can be swapped in both the sauce and topping. This ensures the dish remains gluten-free.