Crumble the yeast and dissolve in approx. 1⁄4 l lukewarm water. Knead with 500 g flour, 1 teaspoon sugar and salt each and 3 tbsp. oil to a smooth dough. Cover and let it rise in a warm place for about 45 minutes.
Clean and wash spring onions and cut the white and green separately into rings. Fry the minced onions in 1 tbsp. hot oil until crumbly. Fry the white of the onions briefly. Season with salt and pepper. Add half the pizza sauce, bring to the boil and simmer for about 5 minutes.
Drain the tuna fish and tear it up. Wash parsley and chop very finely. Mix with 6-8 tablespoons of oil. Season with salt. Wash and quarter the tomatoes. Grate cheese.
Cover three baking trays with baking paper. Knead the dough and divide into about 22 pieces. Roll out round (approx. 9 cm Ø) on a floured work surface. Distribute on the baking trays. Spread half with the rest of the pizza sauce.
Sprinkle with tuna and half of the onion green. Spread the rest of the pizzas with minced sauce. Sprinkle with tomatoes and pine nuts. Sprinkle all pizzas with cheese.
Bake in a hot oven (electric oven: 225 °C/circulating air: 200 °C/gas: level 4) for 12-15 minutes each time. Sprinkle tuna pizzas with parsley oil, sprinkle with the rest of spring onions. Garnish minced pizzas with basil.
Drink tip: strong red wine, e.g. a Chianti.