Remove rind from cheese slices. Peel the pineapple and possibly cut out the stalk in the middle with an apple cutter. Cut the pineapple into 16 thin slices. Mix sour cream and barbecue sauce. Season to taste with a little salt.
Toast white bread light brown. Preheat oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3). If necessary, beat rump steaks 3-4 mm thin between cut open freezer bags. Heat the oil in a frying pan.
Fry the steaks in it for 20-30 seconds on each side. Season with salt and pepper.
Spread each slice of bread with 1-2 teaspoons of barbecue sauce and cover with 1 steak, 2 slices of pineapple and 1 slice of cheese. Bake in a hot oven for 3-5 minutes until the cheese has melted. Serve.