Prepare a yeast dough from flour, sugar, salt, water, olive oil and yeast. After rising, line a greased springform pan with it, forming an approx. 2 cm high rim. Mix the sour cream with the egg yolk and fold in the diced salmon fillet (1.5 cm), the spring onions cut into 0.5 cm slices, the dried tomatoes cut into narrow strips and the squeezed spinach leaves. Season the mixture with salt and pepper (not too much salt, the Gorgonzola also brings something) and pour on the dough. Crumble the Gorgonzola over the mass and drizzle everything with a little olive oil. Bake at 150 ° C for about 30-40 minutes on the middle sliding bar.