Squeeze the orange and lemon. Mix the juices. Reserve.
Remove excess fat and place the meat on the work surface with the lean part upwards and cut it until you get a rectangular shape.
Brush the matambre with the mustard. Place the raw jam over the surface uniformly.
Pour the single cream over the jam.
Add rosemary, ground ají and grated cheese.
Roll meat (be sure that fat is outside) and tie with the matambre thread.
Season to taste.
Sprinkle with paprika.
Wrap with aluminum foil
Bake in the oven for 40 minutes aprox.
Take the meat out. Remove the aluminum foil.
Bake in oven again until golden.
Add the citrus juice from time to time
Place the meat on a dish. Cover with aluminum foil. Rest for 5 minutes.
Remove threads and chop before serving.