In a medium saucepan combine potatoes and water. Bring to boiling; reduce heat. Simmer, covered, for 10 minutes. Add the asparagus; return to simmering. Simmer, covered, for 4 to 6 minutes more or until vegetables are just tender. Drain the vegetables well.
Meanwhile, beat together the egg product, milk, rosemary, pepper, and salt; set aside. In a 10-inch broiler-proof skillet heat olive oil; cook onion and garlic in hot oil until tender. Stir in potatoes and asparagus.
Pour egg mixture into skillet over vegetables. Cook over medium heat. As mixture sets, run a spatula around edge of skillet, lifting egg mixture so the uncooked portion flows underneath. Continue cooking and lifting edges until egg mixture is almost set (surface will be moist). Sprinkle with the feta cheese.
Place broiler-proof skillet under the broiler 4 to 5 inches from the heat. Broil about 1 minute or until the top is just set. Sprinkle with tomato. Cut into wedges. Makes 4 servings.