1-1/2 pounds salmon filet 1 lemon, sliced thin 1/2 onion, sliced thin Salt and freshly ground black pepper 3 Tablespoons unsalted butter 2 garlic cloves, minced 4 sprigs thyme, fresh
Take two large sheets of aluminum foil (large enough to accomodate the salmon with about 4 inches extra on all sides). Lay foil sheets on top of one another and fold up edges to form a lip on all sides.
Arrange onion slices in a single layer on foil. Layer lemon slices on top. Place salmon on top of lemon slices.
Melt butter and combine with minced garlic. Season salmon with salt and freshly ground black pepper. Lay fresh thyme sprigs on top of salmon and drizzle half the garlic-butter mixture over the top.
Turn one side of the grill off and place foil tray of salmon on the "off side" of grill. Close grill lid, allowing salmon to cook for 5 minutes. Turn the other burner off and the one that was off on. Move salmon to the new "off-side". Drizzle remaining garlic-butter mixture over top of salmon. Close grill lid and allow salmon to continue cooking for another 5 minutes or until salmon flakes easily with a fork.
Remove from grill and serve.
If you do not have a two burner gas grill, you can also grill this salmon on a charcoal grill. The only difference is that you will place all your charcoal on one side of the grill. Place the salmon on the other side of the grill, opposite the charcoal. In this case there is no need to rotate the salmon to the other side of the grill. Just continue to cook the salmon checking it for doneness periodically.