Place the lentils in boiling water and cook over medium heat for about 18 minutes. Then pour into a sieve and drain well. Wash the meat, dab dry and cut into thin slices.
Peel onion and chop very finely. Clean, wash and cut the chili into rings. Pour pineapple into a sieve, drain and collect the juice. Wash the lemon thoroughly and peel the skin in fine strips.
Heat the oil in a pan. Fry the meat for approx. 3 minutes, turning it over. Remove from the pan and set aside. Place the pineapple in the pan and fry it until golden brown, also while turning it.
Sauté onion and chilli in the frying fat. Sprinkle with curry and sauté. Deglaze with stock and 50 ml pineapple juice. Bring to the boil. In the meantime stir starch and 3 tablespoons of water until smooth. Stir into the boiling broth and bring to the boil again.
Add lentils, meat, pineapple and lemon peel and simmer for 2-3 minutes at low heat. Season to taste with salt, curry, pepper and sweetener. Serve garnished as desired with pineapple split, lemon balm and lemon slices.