Fry the chorizo in a hot frying pan for 2–3 minutes until golden-brown and the oil is released.
Add the shallots for 1 minute, followed by the roasted peppers, paprika, and tomato purée for 2–3 minutes.
Stir in the canned tomatoes and butter beans and simmer the mixture for 5–6 minutes.
Heat another pan with olive oil and fry the monkfish pieces until they are just browned.
Transfer the monkfish into the stew and simmer for 1–2 minutes until the fish is cooked through.
Stir in the sugar and lemon juice, then season with salt and black pepper.
Garnish the stew with chopped flatleaf parsley.
Combine the lettuce, cucumber, tomatoes, peppers, onion, and asparagus in a bowl.
Whisk the dressing ingredients together and toss with the salad to coat.
Serve the monkfish stew on plates with a side of the prepared salad.