Soak cashews in hot water while preparing the risotto.
Over medium high heat, in a large and deep pan, saute the diced onions and garlic with the herbes de provence in a splash of vegetable broth until they begin to soften. Add chopped mushrooms and saute for 3-4 minutes until the mushrooms soften and reduce, adding a bit of extra vegetable broth if necessary.
Add the arborio rice to the hot pan and saute with the vegetables for a couple of minutes until the rice begins to turn a light golden brown. (*Saute continuously to ensure that the rice does not burn).
Add 2 cups of the vegetable broth and stir until the rice has soaked up the broth. Add a cup more broth and stir continuously until the rice has soaked up the broth. Add the dry white wine (if using) and stir until the rice has soaked up the wine. Add another ½ cup of vegetable broth and continue stirring until the rice soaks up the broth. Continue adding vegetable broth, by the ½ cup, until the rice is just cooked.
Stir in truffle oil, nutritional yeast, lemon juice and frozen peas. Stir for a couple of minutes until the peas are lightly cooked. Add sea salt and pepper to taste.
For the Cashew Cream
Drain and rinse the soaked cashews. Using an immersion blender, blend the cashews, lemon juice, nutritional yeast and water until a creamy and smooth mixture is formed. Add additional water, by the tablespoon, until the desired consistency is reached. Season with sea salt to taste.
Stir the cashew cream into the risotto (or, alternatively, leave the cashew cream on the side and allow people to add it directly to the risotto on their plate) and garnish with fresh basil.