Make the mustard sauce
Recipe and put to one side. Peel and chop the onion, put into a thick bottomed saucepan along with a tablespoonful of olive oil, and soften over a medium heat. When the onion is soft, stir in the peas and rice and take off the heat. Top and tail the courgettes, cut into quarters lengthwise and then into thin slices. Quickly brown the courgette segments in a little olive oil, then take out with a slotted spoon and put to one side.