Preheat the grill to medium high. Brush the salmon with olive oil on both sides.
Make the spices mix by combining the cumin, coriander, paprika, onion powder and garlic powder in a small bowl. Coat the salmon (flesh side, not the skin side) with the spice mix.
While the grill is heating, make the lemon garlic sauce by mixing the minced garlic with lemon juice, olive oil, chopped parsley, salt and pepper in a bowl and set it aside.
To avoid the salmon sticking to the grates, cut a potato in half and rub it on the grill grates. The starch in the potato makes the grates nonstick.
Place the salmon, flesh side down on the grill grates. Grill for 4 minutes until the fillets release themselves and then flip and grill the other side for 5 minutes.
Top with the lemon garlic sauce and serve immediately.