Preheat the oven to 175 ° C top / bottom heat (convection: 150 ° C). In the meantime, roughly dice the onions. Halve the sausage lengthways and cut into slices.
Heat the oil in an ovenproof pan. Sweat the onions and sausage in it for about 5 minutes. Add the tomatoes. Simmer for another 5 minutes. Season the sauce with salt and cayenne pepper to taste. Chop the parsley and stir into the sauce.
Beat the eggs and let them slide into the pan with a little space on top of the sauce. Let it set in the hot oven for approx. 10 minutes.