Pierce potatoes with a fork and cook in microwave for 3-4 minutes, or just until tender. Remove and cut into bite-sized chunks.
In a large bowl, whisk together eggs, flour, milk, and salt. Set aside.
Place a Good Cook 10-inch skillet or cast iron skillet on a large stove burner. Turn heat to medium.
Melt butter in the skillet, add onions, garlic, and chopped potatoes. Cook until the onions are caramelized and slightly golden brown.
Pour the egg mixture into the skillet. Sprinkle asparagus, ham, and cheese chunks around the skillet. Sprinkle with fresh-ground pepper. Immediately turn the heat to low. Cover skillet with a lid (or a large plate). Doing so will allow the frittata to cook evenly through the center, without burning on the bottom. Leave covered and allow to cook over low heat for 10-12 minutes, or until the center of the frittata is set. Remove from heat and allow to set for 1-2 minutes before slicing and serving. Garnish with fresh chopped parsley, if desired.