Squeeze one half of the lemon and use 1 tablespoon of the lemon juice in a large mixing bowl with the smashed garlic clove, anchovies, parmesan and mayo.
Set aside to allow the flavors to meld.
Season salmon with a pinch of salt and black pepper, to taste.
Heat a large skillet over medium-high heat and place salmon skin-side-down.
Cover and cook without turning for 5 minutes, or until the skin browns. Flip and cook an additional 2 minutes, depending on the thickness, until the salmon is cooked through.
Squeeze the remaining lemon juice over the salmon.
Add the lettuce to the bowl and toss well with the dressing until well coated.
Divide the lettuce between plates and top each with salmon.