Wash the meat, dab dry and cut into slices of about 2.5 cm thick. Heat oil in a pan and fry pork medallions on each side for about 2 minutes at medium heat.
Remove meat from the pan. Peel onions and cut into slices. Put them into the pan and fry them in the frying fat while turning for about 8 minutes. In the meantime, wash, quarter, seed and dice the tomato.
Deglaze onions with cream and broth, season with salt, pepper and curry and bring to the boil. Stir in sauce thickener and bring to the boil again. Place medallions in an ovenproof dish, spread onion-cream sauce over them, sprinkle with diced tomatoes and bake in a preheated oven (electric cooker: 200°C/ gas: level 3) for approx. 20 minutes.
In the meantime wash parsley, dab dry and chop coarsely. Sprinkle pork medallions au gratin with parsley and serve garnished with parsley as desired. Croquettes taste good with them.