1. Preheat oven to 400°.
2. Place salt and egg whites in a large bowl; beat with a mixer at high speed until foamy. Add cream of tartar and pepper; beat until soft peaks form. Gently fold in tomatoes and onions.
3. Heat olive oil in a 10-inch ovenproof nonstick skillet over medium-high heat. Spread egg white mixture evenly in pan; arrange ricotta wedges on top. Drizzle with tomato oil. Bake at 400° for 16 minutes or until puffed and golden. Loosen with a spatula; slide onto a platter. Serve immediately. Garnish with parsley, if desired.