Boil rice, quench and chill. Drain the corn and peas, clean the carrots, mushrooms and peppers, cut into small cubes and place in a bowl. Add corn and peas, diced onions and tomatoes. Mix with the rice. Also dice the Gouda and mix well.
Mix a dressing from vinegar, oil, salt and pepper and use it to marinate the salad well. Let the salad stand for about 1 hour, stirring in the meantime.
Tip: This salad can be supplemented with any other ingredients, such as cucumbers or radishes.