Preheat oven to 400 degrees F.
Spray 12 ramekins or custard cups with non-stick cooking spray and set aside.
Bring a teapot of water to a boil and set aside.
Heat butter in a small saucepan and add onion; cook about 2 minutes or until onion is soft.
Add tomatoes, rosemary, salt and pepper to onions and simmer for approximately 8 minutes; add Tabasco sauce (more or less depending on taste).
Spoon 2 tablespoons of tomato sauce into each ramekin; break 1 egg into each ramekin on top of the tomato sauce and sprinkle with salt and pepper.
Arrange ramekins in a baking dish and pour boiling water in dish.
Bake for 10-12 minutes or until whites are firm and eggs are set.
Remove from oven and top each ramekin with 1 tablespoon of sauce and sprinkle with chopped parsley before serving.
Notes and Suggestions
Serve with your favorite crusty bread.