Cook the lentils in boiling water for 6-8 minutes. In the meantime wash, clean and seed the pumpkin. Cut the pumpkin into slices, cut the slices into thin slices. Cut mango from the stone. Peel and chop the flesh.
Rinse meat, dab dry and cut into cubes. Drain the lentils and let them drain.
Heat the oil in a large frying pan. Sauté the meat for about 3 minutes while turning it. Add pumpkin and fry for another 3-4 minutes. Season with salt and pepper. Add lentils, add stock and simmer at medium heat for about 3 minutes.
Wash the coriander, shake dry and chop coarsely, except for a few leaves for garnishing. Add mango and coriander to the pan and stir in. Season to taste with salt and pepper. Garnish with coriander.