Cut the meat into slices, without cutting through to the end, open like a book. Put a plate of bacon in each cut.
Mix the boiled, finely chopped mushrooms and cheese.
Add the pine nuts and crushed juniper berries and mix.
Fill the meat with the mixture.
Tie with bundles or tightly tie with cooking thread, top with salt and pepper.
Put on foil, bake for 20 minutes at 250°C, until Golden brown, then reduce the temperature to 180°C. Bring to readiness, about an hour, depending on the piece of meat.
Cover with foil only if the meat starts to turn very red. At the end, remove the bundles, tuck the edges of the foil and serve.