Press artichoke hearts between layers of paper towels to remove excess moisture. Combine tomato and green onions in a small bowl; set aside.
Cook artichoke hearts and garlic in butter in a small nonstick skillet over medium-high heat 2 minutes. Set aside.
Combine egg substitute, pepper, and hot sauce in a small bowl. Pour about 1/2 cup egg substitute mixture into each of 4 individual oven-proof au gratin dishes coated with cooking spray. Sprinkle with Parmesan cheese. Dot each frittata with cream cheese and sprinkle with tomato mixture. Bake on top shelf of oven at 350° for 5 to 7 minutes or until edges begin to set, but center is still soft. Turn oven to broil. Top frittatas evenly with artichoke mixture. Broil 3 inches from heat 3 to 4 minutes or until browned and set. Serve immediately.