Preheat the oven to 425 degrees F.
Place cauliflower florets on a microwave-safe plate and cover with wet paper towel.
1 small head cauliflower,
Microwave on high for about 5 minutes, until crisp-tender.
Place the cauliflower in a single layer into an 8x8 inch baking dish.
Melt butter in a small sauce pan over medium heat.
4 Tbsps butter
Add flour and whisk until it makes a bubbly paste.
3 Tbsps all-purpose flour
Gradually add milk and stir until the sauce becomes thick and creamy.
1 ½ cups milk
Remove from heat and add salt, pepper, nutmeg and ½ cup of the Swiss cheese. (Do not add the parmesan yet.)
Sea salt and ground pepper,, ¼ tsp teaspoon ground nutmeg,, 1 cup grated Swiss cheese,
Spoon the sauce over the cauliflower florets and sprinkle with remaining ½ cup Swiss cheese as well as the ¼ cup Parmesan cheese.
¼ cup shredded parmesan
Bake uncovered for 15 to 20 minutes until the cheese sauce is soft and slightly golden.