how to cook salmon on a plank on weber grill
1 Place the plank on the grill rack and allow it to preheat for about 5 minutes, or until it begins to crackle and smoke. 2  Lay the salmon onto the plank, cover the grill, and allow the salmon to cook for 18 to 22 minutes, depending on its thickness. 3  To test for doneness, insert a fork into the thickest part of the salmon.tep 2: Prepare the plank. Plank-grilling gives salmon the flavor imparted by a smoker with the convenience of a grill. Be sure to prepare your wood properly to increase moisture for cooking and prevent burning. Take these steps to prepare your wooden grilling plank: 1  Rinse the plank with water to remove any dust.