Heat the oil and butter in a large non-stick frying pan, then add the courgette, peppers, potatoes and a little salt and pepper. Cook for 10 mins, stirring from time to time until everything is starting to brown. Add the spring onions, garlic and thyme and cook for 2 mins more.
Make four spaces in the pan and crack in the eggs. Cover with foil or a lid and cook for around 4 mins, or until the eggs are cooked (with the yolks soft for dipping into). Sprinkle with more thyme leaves and ground black pepper if you like. Serve with toast.