Cook ground beef and onion in 10-inch skillet over medium-high heat, stirring occasionally, 8-10 minutes or until browned. Drain off fat.
Stir in potatoes, salt and pepper. Cover; continue cooking, stirring occasionally, 8-10 minutes or until potatoes are tender. Stir in salsa. Continue cooking 1-2 minutes or until heated through. Remove from heat.
Arrange cheese quarters over top. Top with olives and green onions. Cover; let stand 3-4 minutes or until cheese is melted.
Leftover chopped cooked potatoes may be substituted for frozen potatoes. Use your favorite level of heat for salsa.