Heat a 10-inch cast-iron skillet over medium-high heat and add cauliflower crumbles to the skillet with 1/4 cup water.
Cover the skillet to cook the cauliflower rice until it softens, about 8 minutes. If you're using frozen cauliflower rice that's been pre-thawed, then you may only need to cook 3-5 minutes. For fresh cauliflower rice, it will take closer to 8 minutes.
While the cauliflower rice is cooking, mix eggs, milk, garlic powder, thyme, salt and pepper with a hand mixer until fluffy, about 3 minutes.
Chop the kale then add it to the skillet with the cauliflower rice stirring to combine. Cook until the kale has wilted about 2-3 minutes then remove the vegetables from the skillet and add them to the egg mixture.
Spray the skillet with nonstick cooking spray and add the eggs and vegetables back into the skillet, sprinkle with parmesan, cover and cook until the edges are set, about 5 minutes.
Meanwhile heat the oven broiler to high. After 5 minutes, remove the cover and place the skillet in the oven for 8 minutes until the top of the frittata is fully cooked.
Slice into 2 large slices and serve or store in the refrigerator up to 5 days.
Video
Notes
Remove the frittata from the oven when the center becomes less jiggly to avoid overcooking it.
Use frozen cauliflower rice to reduce prep time and clean up. Just be sure to thaw it out and drain it before adding it to the skillet.
Transfer your frittata from a skillet to a baking dish if you don’t have an oven-safe or cast-iron skillet.