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A close-up shot of the root vegetable bake, highlighting the creamy sauce and perfectly roasted carrots, broccoli, and cauliflower.

Winter Vegetable Casserole (The Ultimate Cozy Recipe)

This hearty winter vegetable casserole features roasted seasonal vegetables in a rich, creamy cheese sauce. It's the ultimate cozy, comforting, and make-ahead friendly dish for any occasion.
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Prep Time 25 minutes
Cook Time 45 minutes
Total Time 1 hour 10 minutes
Servings: 8 servings
Course: Main Course, Side Dish
Cuisine: American
Calories: 350
Ingredients Equipment Method Notes

Ingredients
  

  • 8 cups Mixed Winter Vegetables (Carrots, broccoli, cauliflower, sweet potatoes, parsnips), cut into 1-inch pieces
  • 3 tbsp Olive Oil
  • 1/4 cup Unsalted Butter
  • 1 large Yellow Onion Finely chopped
  • 4 cloves Garlic Minced
  • 1/4 cup All-Purpose Flour
  • 2 cups Whole Milk
  • 1 cup Vegetable Broth
  • 1 tsp Dried Thyme
  • 1 1/2 tsp Salt Or to taste
  • 1/2 tsp Black Pepper Freshly ground
  • 1 1/2 cups Gruyère Cheese Shredded, divided
  • 1/2 cup Parmesan Cheese Grated

Equipment

  • 1 Large Baking Sheet
  • 1 9x13 inch baking dish
  • 1 Large Skillet

Method
 

  1. Preheat oven to 400°F (200°C). On a large baking sheet, toss the chopped vegetables with olive oil, 1 tsp salt, and 1/4 tsp pepper. Spread in a single layer and roast for 20-25 minutes until tender and lightly browned.
  2. While vegetables roast, melt butter in a large skillet over medium heat. Add onion and cook until soft (5-7 mins). Stir in garlic and cook for 1 more minute.
  3. Sprinkle flour over the onions, cooking for 1 minute while stirring. Slowly whisk in milk and vegetable broth until smooth. Simmer until thickened, about 5-8 minutes.
  4. Remove sauce from heat. Stir in thyme, remaining salt and pepper, 1 cup of Gruyère, and the Parmesan cheese. Stir until fully melted and smooth.
  5. Add the roasted vegetables to the cheese sauce and stir to combine. Pour into a 9x13-inch baking dish. Top with the remaining 1/2 cup of Gruyère. Bake for 20 minutes until hot and bubbly. Rest for 10 minutes before serving.

Notes

Tip 1: Cut vegetables into uniform 1-inch pieces to ensure they cook evenly.
Tip 2: Shred your own cheese from a block for the smoothest, creamiest sauce.
Tip 3: Don't crowd the vegetables on the baking sheet; use two if needed to make sure they roast instead of steam.