Heat the oil in a 3 quart sauce pot, add the onion or shallot and cook over medium heat for 1 minute or until translucent.
Add the rice, stir to coat with the oil and cook for 2 minutes more. Add the wine.
Increase the heat to medium high and add ladles of chicken stock, about 4 oz (½ cup) at a time, cooking until the liquid is absorbed before adding another ladle.
After half of the stock has been added the rice should be about half cooked. From here you can spread the rice on a tray to cool so it can be heated up quickly, or continue cooking.
In a separate pan, heat another tablespoon of oil and cook the mushrooms until wilted and season with a pinch of salt. Add the mushrooms to the rice, and continue cooking, adding the rest of the chicken stock until the rice is just tender and cooked through.
Add the peas, butter and basil and heat through. Turn the heat off.
Add the cheese, lemon zest and juice and stir vigorously. The risotto should be juicy enough to lay flat in a bowl. Double check the seasoning for basil, lemon and salt, then serve immediately. Garnish with a few tiny basil leaves if you like.