Finely slice the peppers, leek and the garlic.
Heat 2 Tbsp of the olive oil in a frying pan. Add the sliced vegetables and sauté for 10 minutes on a low heat. Add a drop of water or white wine if the vegetables are sticking. Add the sage and season with salt and pepper.
Transfer the vegetables to a plate, dry the pan with kitchen paper and heat the remaining oil. Season the pork with salt and pepper then fry in the hot oil on a medium heat for two minutes on each side.
Remove the meat and let it rest.
Meanwhile deglaze the pan with the lemon juice, add the vegetables and warm through.
Serve the escalopes with the vegetables.