Crush the juniper berries with the back of a knife. Finely chop rosemary leaves. Mix prepared spices with salt and pepper.
Grate the venison with some of the spices. Fry it in a pan on all sides in a small amount of olive oil until golden brown, 3-4 minutes on each side.
Crush the garlic, mix with the remaining spices and rub the venison with them.
Bake at 170 °C. Cook for 8 minutes, until the temperature reaches 50°C in the middle of the piece of roast beef. Remove from oven, let rest on a cutting board and cut into thin slices.