Using 1 tablespoon butter, grease bottom and sides of a 11-inch deep dish ceramic pie plate, set aside.
Preheat 1 teaspoon olive oil in a 10-inch non-stick skillet, over medium-high heat.
Sauté onion, bell pepper and mushrooms until mushrooms are shrunk and light brown.
Add asparagus, continue cooking until crisp tender; add a little water (1/8 cup) to steam vegetables quickly and deglaze pan.
Stir in garlic, rosemary, salt and black pepper; cook 1 minute. Remove vegetable mixture from heat and place onto plate lined with paper towel to absorb excess moisture; cool.
Meanwhile, preheat oven to 350°F. Line the bottom of pie plate with shredded potato. Layer 1/4 cup shredded or 2 slices of cheese over potatoes.
Place cooled vegetable mixture and diced chicken over cheese/potato layer; set aside.
In medium bowl, combine eggs, half and half with milk; whisk. Slowly pour over chicken and vegetable mixture. Place remaining cheese over egg mixture. Garnish with asparagus tips; gently press into egg/cheese mixture. Making sure you do not submerge the tips completely.
Place in preheated oven on the lowest rack setting; bake 20 minutes at 350°F. Move to second rack placed in the center of the oven; continue baking for another 20 minutes. Frittata should be cooked when golden brown and firm. Check by inserting a knife in center of pie. Cool 15 minutes before serving. Slice into 6 wedges and serve with fresh fruit.
This would be great prepared in a 12-Inch cast iron frying pan or any dish of similar size.