Frittata of Kale with Sweet and Purple Potato

Traveling in China, I was often served purple potatoes; I had no idea they were so popular.  But here in the United States, they seem to be a delicacy, but on the rise.  I like them for their sweetness and color - they must have antioxidants.  As Michael Pollen says - eat lots of color!
1 medium sweet potato, peeled, cubed to 1/2 inch; about 1-2 cups
2 purple potatoes, peeled and diced, about 1-2 cups
1 medium onion diced
6 cups chopped kale
3 cloves garlic, minced
1 red Serrano chili, diced
8 eggs
1/2 cup half-&-half or light cream
1/4 lb Monterrey Jack (or other) cheese, diced
Fresh grated nutmeg; just a bit
2 Tbsp fresh chive, minced

Preheat oven to 375F. In a large oven-going non-stick skillet, sauté potatoes and onion for about 15 minutes in a bit of olive oil.

In another large skillet, heat the kale with a tablespoon olive oil and 2 Tablespoons water.  Cover and cook on low heat for about 10 minutes, stirring every so often.  Then remove the top and let the kale dry out a bit, being careful not to burn the kale.

Whisk together the eggs, cream, chives and nutmeg. Salt and pepper to taste. Toss the kale with the potatoes in the pan and turn heat to medium-high. Add eggs to pan and let eggs set a bit. Lift eggs and tilt pan to redistribute uncooked egg. Distribute cheese evenly into uncooked egg.

After eggs have set just a bit, and you can see steam bubbles coming through the egg surface, place in oven and bake for about 10-15 minutes.  Finish under the broiler to brown up just a bit, if necessary.

Serves 4.