Heat oil in a large heavy based saucepan, add red onion and garlic and sauté gently for 1 minute, then add risotto rice and toss for 2 minutes to coat the grains in oil.
Gradually add 1/2 cup of stock at a time, stirring until liquid is absorbed before adding more.
Cook for 12-15 minutes until the risotto rice is al dente.
Stir in mushrooms and snow peas and cook for 2-3 minutes until mushrooms are cooked, then lastly stir through Tatua Mascarpone, dill, lemon zest and season well.