Preheat oven to 375 degrees.

In a large pot bring 4 quarts of water to a boil.

Chop cauliflower head up in small chunks. Blanch cauliflower chunks by boiling for 3 minutes and transferring chunks with a slotted spoon to an ice bath (a large bowl filled with ½ water and ½ ice).

Continue the same blanching process with kale, but only boil for 30 seconds to – 1 minute, transfer kale to ice bath. Chop kale and drain all water from the cauliflower.

In a large saucepan simmer butter and flour together to make a “roux” When mixture looks like cookie dough consistency and light brown in color, pour milk and whisk constantly. Bring mixture to a strong simmer and thickened in consistency.

Remove roux from heat and add thyme, rosemary, garlic, salt, pepper, cayenne, nutmeg, and cheeses until melted.

Mix cheese sauce, cauliflower, and kale together in a large bowl.

Transfer mixture to a casserole dish and bake for 45-60 minutes or until cheese has browned on top.