1. Snip chives. Heat Oil in (large 10in) skillet over medium high heat until hot. Add asparagus, potatoes and galic pressed with garlic press; cook and stir 4 min. Reduce heat to low. Sprinkle chives, 1/2 cup of the cheese, salt and black pepper over mixed potato mixture. Cover; cook 14-15 min or until egg mixture is set in center. Remove from heat.
2. Meanwhile, slice tomatoes, arrange tomato slices in an overlapping circular pattern over top of frittata. Sprinkle with remaining cheese. Cover; let stand until cheese is melted. Garnish with additional snipped chives if desired. Cut into wedges.