Pile some dry firewood (birch or other wood) on the gridiron of the grill. Place sufficient charcoal and a little lighter fluid over the firewood, light the fire and let it burn a while with the ventilation seal open under the grill. Cover the lattice grill with a sheet of aluminium foil covering the upper and lower edge. The fat will drop into the fire leaving the surroundings of the grill clean. When the fire is burning well with good embers, you can gradually begin to close the ventilation seal.
Fillet the fish (fatty fish such as salmon are best for this type of cooking) and remove any remaining bones. Place the fillet on the aluminium foil (skin facing the foil) and lock the fish into the lattice with the help of the stainless steel wire tray. Place the lattice near the heat of the fire at a slight angle away from the glow.
Place your hand between the embers and the fish to judge the right distance. If you don't burn your hand, the distance is right for glow frying. Baste the fillet with melted butter, which contains added salt. You can also salt the fish 2 - 3 hours before cooking. In that case extra salt is not needed to melted butter. As the lower part of the fillet is usually fried earlier, you can easily turn the lattice grill upside down.
Then the reverse side of the fillet is closer to the heat. This is a safe way to grill over an open fire, as a wooden grilling board is always in danger of being burnt. Add firewood little by little.
Grease the lattice grill with cooking oil and place the small fish on the lattice. Place the adjustable stainless steel wire tray on the fish tight enough so that the fish will not fall off when turning the lattice.