Cut the meat lengthways so that a large meat platter is created. Season these vigorously on both sides with salt, pepper, paprika and garlic and sprinkle with parsley. Now distribute the onion rings, tomato peppers and garlic slices evenly on top. Roll up into a giant roulade and tie together with kitchen thread or heat-resistant silicone straps.
If the roast is to be cooked in the oven, cook it in the open roaster with a little water (add more water if necessary) in a preheated oven at 180 degrees for approx. 1 1/2 hours, turning it more often. But you can cook it in the roasting tube at the same time. This creates a wonderful meat juice. If, however, it is to be grilled on the charcoal handle, it is pushed onto a grill skewer, fastened with clamps and grilled with constant rotation, e.g. with a motor, in about the same time.