- 1 large head cauliflower, cut into small florets and stems reserved
- 2 tablespoons grated Parmesan cheese
- 1 teaspoon dried chopped chives (optional)
- 2 tablespoons butter
- 1 tablespoon chopped shallot
- 1 tablespoon minced garlic
- 1 cup vegetable broth
- 1 cup heavy whipping cream
- 2 tablespoons prepared horseradish
- salt and ground black pepper to taste
- 2 tablespoons heavy whipping cream (optional)
- 1/2 cup shredded Gruyere cheese, or more to taste
- Chop cauliflower stems into small pieces. Measure out 1/2 cup of cauliflower florets and chop into small pieces. Set aside.
- Bring a large pot of lightly salted water to a boil. Add cauliflower florets and cook uncovered until crisp tender, 4 to 5 minutes. Drain. Toss with Parmesan cheese and chives.
- Preheat oven to 425 degrees F (220 degrees C).
- Melt butter in a skillet over low heat. Add reserved stems and chopped florets, shallot, and garlic; cook and stir until tender but not brown, 3 to 5 minutes. Pour in vegetable broth and bring to a boil. Cook over high heat until broth evaporates completely, 8 to 10 minutes. Remove from heat.
- Pour 1 cup heavy cream into the skillet and puree mixture with an immersion blender until smooth. Stir in horseradish, salt, and black pepper. Transfer to a baking dish and add blanched florets; toss to coat evenly with cream mixture. Drizzle with 2 tablespoons heavy cream and top with Gruyere cheese.
- Bake in the preheated oven until golden brown, 20 to 30 minutes.