Heat the olive oil in a large pan and sauté the onions, fennel, diced chorizo, chilli, ground fennel seeds and garlic for a few minutes.
Add the paprika, thyme, saffron, bay leaves and tomatoes and cook until reduced to a thickish sauce.
Add the fish stock (or water) and white wine and bring to a simmer.
Add the cooked mussels and cook until they are all open. Discard any that have not opened.
Put the fish pieces into the stew and stir in the almonds.
Heat for a minute or two and serve with seasonal greens, steamed potatoes and wedges of lemon.