Add the rice to a small pot and ladle the hot stock over it. Cover and boil for 7 minutes, then drain off any excess stock. In a large nonstick pan, add a knob of butter and gently fry the garlic until it begins to sizzle, then stir in the rice and a pinch of salt. Wrap the lid of the pan with a tea towel and cook for 25 minutes on a low heat. After 10 minutes, add the peas and replace the lid.