Creamy Cauliflower (Fauxtato) au Gratin

Ingredients (12)

• + 2 heads cauliflower, cored and cut into florets add to pantry
• ✓ 2 tablespoons butter, or as needed
• + 1 tablespoon all-purpose flour add to pantry
• + ½ cup chicken stock add to pantry
• + ¼ cup half-and-half add to pantry
• ✓ ¼ cup shredded Parmesan cheese, divided
• + ¼ cup shredded mozzarella cheese, divided add to pantry
• + ¼ cup snipped fresh chives add to pantry
• + ½ teaspoon salt, or to taste add to pantry
• ✓ ¼ teaspoon ground black pepper, or to taste
• + 1 pinch ground nutmeg add to pantry
• + 1 pinch red pepper flakes add to pantry