Rinse the sirloin steak and pat it dry with kitchen paper. Cut streaks into the fat layer of the sirloin steak with a sharp knife, being careful to cut only through the fat.

Place the tenderloin in an ovenproof dish. Dissolve the meat stock in water, and pour the stock into the dish so that it reaches the meat (but not over the fat).

Season the fat side with salt. Add a little butter to the broth if you want to enhance the flavor. Add cloves, bay leaves, peppercorns, and juniper berries to the broth.

Preheat the oven to 150°C. Place the baking dish in the oven and bake the tenderloin for 1½ to 2 hours, depending on the size of the steak. Remove the tenderloin from the oven and pour off the liquid (reserve it if you plan to use it in a sauce).

Preheat the oven to 220°C. Season the fat side well with salt and return the steak to the oven. Cook until the fat is golden brown and crispy, about 15 minutes.

Remove the steak from the oven and let it stand for a few minutes before cutting into slices.