Put the couscous in a bowl. Bring 300 ml vegetable stock to the boil with the kettle, pour over the couscous and leave to swell for about 10 minutes.
Fry the ground beef in a non-stick pan until crumbly. Add the mustard and ketchup and stir. Peel the carrot and cut into small pieces, put the peas in a colander and rinse. Add the carrots and peas to the pan, mix with sour cream and then season with paprika powder.