PREHEAT oven to 350° F.
SPREAD 2 tablespoons pesto on salmon. Set aside.
COMBINE remaining pesto with zucchini, bell peppers, fennel and onion in a large bowl. Toss to coat. Spread onto a large baking sheet with sides. Bake for 20 minutes.
STIR vegetables and make a space in center. Place salmon in open space and cover with lemon slices. Bake for an additional 20 minutes or until salmon is cooked through and vegetables are tender. Cut salmon in half before serving.
