Fry the shallots, garlic and red chili for a few minute until it starts to get golden brown.
Add the tomato paste and fry for 1-2 minutes.
Add fennel, leek and carrot and fry for another few minutes.
Add crushed tomatoes, water, white wine (if using), stock cube, orange juice and zest to the pan and stir to combine.
Taste to check the seasoning and add more salt, pepper, stock cube or orange juice if needed.
Add the diced cod, salmon and mussels and cover with a lid. Cook for 2-3 minutes, just until the fish is done and the mussels have opened. Don't cook for too long, you don't want the fish to get over cooked.
Divide the fish soup between two plates, garnish with peeled shrimps, shaved fennel and creme fraiche or aioli (if using).