Roast the almonds in a dry frying pan over a medium heat for a few minutes until toasted.
Cut the monkfish into 8 evenly sized pieces. Spread the onion over the base of a medium-sized flameproof casserole and arrange the monkfish over the top. Season to taste with salt and pepper and drizzle over a little oil. Cover tightly and cook over a medium heat for 5–6 minutes.
Meanwhile, in a food processor add the almonds, garlic, saffron and parsley, and blitz until finely chopped. Add 2–3 tablespoons water and blitz again to make a coarse paste.
Remove the lid from the casserole, spread the almond mixture over the top of the fish and add the peas. Re-cover and cook for a further 4–5 minutes or until the fish is cooked through. Serve immediately.