Wash the sage and dab dry. Wash rosemary, dab dry and pluck needles from the stalks. Peel garlic and cut into small pieces. Chop or mortar 2 tablespoons of olive oil, peppercorns, fennel seeds, sage, rosemary, garlic and 2 teaspoons of salt together until a paste is formed. Wash the meat, dab dry and rub with the paste. Place the meat on the grid of the oven, insert a fat pan underneath and cook in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 30-40 minutes (using a roast thermometer in the core to approx. 70 °C), remove and allow to cool.
Peel the onions and cut them into rings about 1 cm (1/2 inch) wide. Heat 1 tablespoon of oil in a frying pan. Sauté onions until translucent, remove from heat, add 2 tbsp. oil and balsamic vinegar. Season with salt and pepper and let cool off. Toast the sandwich slices. Remove meat from the bone and cut into very thin slices across the meat fibre. Cut cheese into 8 slices. Divide meat slices into 4 portions and place them in 4 stacks on a baking tray lined with baking paper. Cover with onion slices and 2 slices of cheese each. Bake in a preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: stage 1) for 3-4 minutes until the cheese has melted.
Toast the sandwich slices. Remove meat from the bone and cut into very thin slices across the meat fibre. Cut cheese into 8 slices. Divide meat slices into 4 portions and place them in 4 stacks on a baking tray lined with baking paper. Cover with onion slices and 2 slices of cheese each. Bake in a preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: stage 1) for 3-4 minutes until the cheese has melted. Coat 4 sandwich slices with 1 tsp. Harissa each. Remove the meat and place 1 stack on each coated sandwich slice. Place the remaining sandwich slices on top and press down slightly. Pin and halve the sandwiches
Coat 4 sandwich slices with 1 tsp. Harissa each. Remove the meat and place 1 stack on each coated sandwich slice. Place the remaining sandwich slices on top and press down slightly. Pin and halve the sandwiches
Waiting time approx. 1 hour