Roll out the pizza dough on a parchment-lined baking sheet. Mix the tomato sauce with the ketchup, tartar sauce and mustard and season with salt and pepper. Preheat the oven to 200 ° C (top / bottom heat, convection not recommended).
Drain the sausages and cut them into slices. Drain the cucumber slices and cut in half. Spread the tomato sauce on the pizza dough. Top with the sausages and cheese.
Bake the pizza in the oven on the lowest rack for about 20 minutes. Cut the pizza into 4 pieces, arrange the fried onions and cucumber pieces on top, serve.