Season pork medallions with salt and pepper. Heat 2 tablespoons of oil in a pan and fry the medallions in 2 portions for about 3 minutes on each side. Remove the meat from the pan and wrap it in aluminium foil.
Dissolve the gravy with white wine and stock, bring to the boil and cool in a bowl. Put corn and beans in a sieve each and let them drain. Rinse beans with cold water. Wash parsley, dab dry and chop the leaves.
Peel onion and cut into thin rings. Wash and halve the tomatoes. Cut cheese into small cubes. Clean the rocket. Put everything in a bowl. Mix the cooled stock with vinegar and 2 tablespoons of oil and season with salt, pepper and a little sugar.
Add to the salad. Add medallions to the salad and arrange on 4 plates.