Thaw the pikeperch fillets (if frozen), wash, pat dry, season with salt and pepper.
Dice the paprika, cut the shallot into slices and sauté both in 1 tablespoon butter until translucent. Add paprika, thyme leaves, pressed garlic, fill up with 3/4 of the fish stock, bring to the boil and cook over low heat for 15 minutes. Puree the paprika stock in a blender, pour through a fine sieve into a saucepan.
Fry the spring onions with 1 tablespoon of butter in a pan, fry the fish briefly on both sides, add the paprika stock and reduce by half.