Wash the mussels and remove any broken ones.
Cook the mussels and remove the mussel meat from the shells. Keep a few mussels in their shells aside for garnishing. Set the mussel broth aside.
Heat two tablespoons of olive oil in a deep pan over medium heat and sauté the shallot and fennel until translucent and soft. Add the rice and stir-fry for 2 minutes until the grains are translucent. Deglaze with the wine and pour in the mussel broth. Now, add some fish stock each time the rice has absorbed most of the liquid. Keep stirring well. Once the rice is cooked, after about 20 minutes, stir in the butter. Mix in the mussel meat, parsley, and samphire, and season the risotto with a bit of salt and pepper, if necessary. Be careful, as the dish may already be quite salty from the mussel broth and samphire.
Serve the risotto as desired with some mussel shells and extra parsley.