Preheat oven to 180C. Heat oil in a frypan over medium heat and cook onions for 3-5 minutes until soft and lightly golden. Set aside.
Lightly oil a 4-hole (200ml each) muffin tray. Line each hole with a quarter of the wrap or enough to fill the muffin hole. Divide onion, basil and tomatoes into each tart and crack an egg on top. Cook for 25 minutes or until whites of the eggs are just cooked. Garnish with basil.