Pike Place Market Cookbook- Barbecued Salmon

Today I received a very interesting book from Paperbackswap, Pike Place Market Cookbook . I have been interested in the market since I read the book Fish! A Remarkable Way to Boost Morale and Improve Results that featured Pike Place Fish. The cookbook gives a history of the market and talks about the seasonal variations in merchants and items available. It features recipes that were submitted to the author by the various merchants.
Here is the recipe submitted by Pike Place Fish.

Barbecued Salmon

1 teaspoon garlic powder
1 teaspoon pepper
1 teaspoon salt (optional)
5 pounds salmon, cut into book fillets
1 medium onion, sliced into 1/4-inch rounds
2 lemons, sliced into 1/8-inch rounds
Mix garlic powder, pepper and salt (if used) in a small bowl. Sprinkle spice mixture evenly over flesh side of fish. Place onion and lemon sliced evenly over seasonings on flesh side of fish. Place salmon skin side down on grill (coals should be at 350 degrees), cover, and cook 15 to 20 minutes, depending on thickness of fish and the way you like it cooked. If you don't have a barbecue grill, you can still try this dish by baking instead of grilling it. To bake fish,place fish skin side down in a shallow baking pan that has been lightly greased or sprayed with nonstick corn-oil or olive-oil spray. Prepare as above and bake about 10 to 15 minutes without turning, depending n the thickness of the fish. Serves 8.