Place the salmon in a bowl. Season with salt and pepper. Pour in the olive oil and mix carefully to avoid the fish from breaking apart. Add the mushrooms and bell pepper and toss a few times.
Thread the salmon, mushrooms and bell peppers on the skewers alternately, starting and ending with a piece of salmon.
Now, this is important: brush the grill with vegetable oil before laying the kebabs to make sure nothing sticks.
Grill the kebabs over medium heat, about four minutes on each side, brushing on the glaze as the kebabs cook.
Do not wait until the fish is completely opaque. The fish will continue cooking after the skewers are removed from the grill so while the centers are still a bit pink, transfer them to a plate.
Brush the cooked salmon and portobello mushroom kebabs with more glaze before serving. Best with rice.