Knead the dough ingredients using a mixer with a dough hook, then knead by hand to form a smooth dough. Brush the baking sheet with olive oil and dust with flour. Roll out the dough on the baking sheet.
Slice the sausages into even slices. Spread the ketchup on the pizza dough and top with the sausage slices. Spread the remoulade and mustard in a wave pattern over the pizza. Drain and top with the pickled cucumbers. Scatter the fried onions over the top. Sprinkle the grated Emmentaler and cheddar cheese thickly over the pizza.
Bake on the middle rack at 200°C (392°F) with top/bottom heat for 20 minutes, then at 180°C (356°F) with convection for 10 minutes. Finally, use bottom heat only for 5 minutes until the crust becomes crispy.