Take out the store-bought puff pastry ahead of time, thaw it and cut into squares: two rectangles of dough make 4 tarts.
On each square, lightly score the borders with a knife about 1 cm from the edge, without cutting the dough all the way through. Prick the inner surface with a fork.
Wash the vegetables. Finely dice the zucchini and pepper, slice the tomato into rounds, grate the cheese and finely chop the parsley.
Arrange the vegetables on the tarts without going past the borders, top with a tomato slice and sprinkle with grated cheese.
Bake in an oven preheated to 200°C for 12-15 minutes.
Take out the tarts, carefully crack an egg into the center of each, add a couple of onion rings and return to the oven for 5-7 minutes, until the eggs are set.
Season the finished tarts with salt, pepper and a sprinkle of chopped herbs.