Put the flour in a bowl. Crumble yeast into it. Add sugar, salt, oil and 150 ml lukewarm water. Knead to a smooth dough with the dough hooks of the hand mixer. Cover and leave to rise in a warm place for about 30 minutes.
Knead again, cut in half and roll out on a floured work surface to two round bases (approx. 20 cm Ø). Place on a baking tray lined with baking paper, spread with chunky tomatoes and pre-bake in a preheated oven (electric cooker: 200 °C/ gas: level 3) for approx. 15 minutes. Clean, wash and chop the spring onions. Drain the seafood and spread on the pizzas with the spring onions. Season with salt and pepper, sprinkle with cheese and bake for another 10 minutes