Drain the corn in a sieve. Peel and finely chop the onion. Heat oil in a pan. Crumble the minced meat into it and fry it vigorously while turning. Add the onion and fry briefly.
Mix in the corn. Season with salt, pepper, paprika, sugar and ketchup. Remove from the stove. Take the pizza dough out of the fridge, roll out on a baking tray on baking paper. In the meantime wash and clean the tomatoes and cut them into thin slices.
Halve the yeast dough lengthwise and then cut each strip into three. Put 3 tomato slices aside. Spread the remaining tomato slices on 3 small pizzas. Spread half of the minced meat mixture on top and sprinkle with half of the cheese.
Spread the remaining mince mixture on the remaining 3 dough pieces, leaving about 1.5 cm of edge free. Cover with a slice of tomato and fold over. Press the edges together with a fork. Sprinkle with remaining cheese.
Bake in the preheated oven (electric range: 225 °C/ convection oven: 200 °C/ gas: level 4) for 12-15 minutes on the lower rack. Remove from the oven and serve immediately.