4 C. Wirthy Salmon fillets, thawed

6 tablespoons mayonnaise
5 tablespoons minced fresh basil
1 teaspoon grated lemon peel
3 tablespoons olive oil
1 tablespoon fresh lemon juice

8 bacon slices
1 small red onion, sliced
8 1/2-inch thick sourdough or country style white bread slices (each about 5x3 inches)
8 tomato slices
8 lettuce leaves

Mix mayonnaise, 2 tablespoons basil and lemon peel in small bowl to blend.  (Can be made 1 day ahead.  Cover and chill.

Mix remaining 3 tablespoons basil, olive oil and lemon juice in large glass baking dish.  Add salmon to oil mixture; turn to coat.  Cover; chill 1 to 4 hours.

Cook bacon in heavy large skillet over medium-high heat until crisp.  Using tongs, transfer bacon to paper towels to drain.  Add onion to drippings in skillet.  Sauté until onion is tender and beginning to brown, about 5 minutes.

Prepare barbecue. (medium-high heat).  Grill fish until just opaque in center, about 3 minutes per side.  Grill bread just until golden, about 2 minutes per side.

Spread mayonnaise mixture over 1 side of bread slices.  Top each of 4 bread slices with 2 bacon slices, 2 tomato slices, 1/4 of onion, 1 salmon fillet and 2 lettuce leaves.  Cover with remaining bread slices.