Roll or stretch dough into a very thin disc (or somewhat more rectangular shape if you want) and lay on a baking sheet.
Sprinkle with whole fennel seeds and freshly cracked black pepper, press slightly into the dough and bake in the oven for about 6-8 minutes until it starts to colour and becomes nice and cripsy.
Take the crust out of the oven and spread mustard thinly all over the crust. Cover with alfalfa and sunflower seed sprouts.
Add dollops of yogurt here and there, then break the herring into smallish pieces and scatter them across the pizza.
Finish with the baby arugula, onion slices and capers.