Cook the rice according to the instructions on the packet, pour over a sieve, rinse with cold water and drain.
Peel and dice the onion. Peel and core half the peppers, remove the white dividers and also dice. Clean the leek and cut into rings.
Heat the fat in a pan on medium heat and sauté the onion cubes. Add the peppers and the leek and let them steep for about 5 minutes, covered.
Put the cooled rice in a larger bowl and fold in the stir-fry vegetables. Season to taste with oil, lemon juice, salt and pepper and mix in the finely chopped parsley.
Peel the mango piece, dice it, add it to the salad and season to taste.