Prawn, fennel and avocado risotto

Preheat the oven to 220°C.
Place the mussels in a bowl of icy water in the fridge while preparing the vegetables.
Thickly slice the fennel, then place on a baking tray lined with baking paper with the whole tomatoes and unpeeled garlic. Drizzle with olive oil and season with salt. Roast for 30 minutes, or until the tomatoes are soft and starting to char.
Meanwhile, clean the mussels, discarding the beards.
Peel the tomatoes and garlic and chop the fennel, then blend to form a purée. Add the tomato paste and a few twists of pepper. Pour into a large saucepan.
Add the stock concentrate and simmer briskly for a few minutes to reduce slightly. Add the mussels, cover tightly and cook over a high heat for 5 minutes, or until the mussels have opened. Discard any that do not open.
Mix the mussels with the cooked drained pasta. Turn into wide bowls for serving and garnish with chopped fennel fronds. Season to taste.