In a pan, brown the chopped onion in butter or extra virgin olive oil, add the artichokes (which have been soaked in water and lemon juice) and cut into strips. Cook for a few minutes, then add the rice and toast for about 3 minutes. Add the wine over a high heat, then lower the heat and continue cooking, gradually adding vegetable stock. Stir in a teaspoon of butter off the heat before serving. Sprinkle each portion generously with Stefania Calugi Truffle Petals.