In a food processor or blender, combine the basil, almonds, Parmesan, garlic, lemon juice, salt and a few twists of freshly ground black pepper. Process the pesto while slowly drizzling in the olive oil, until the mixture is relatively smooth and uniform.
Preheat oven to 425 degrees Fahrenheit. Prepare the broccoli rabe by rinsing it and patting it dry. Slice off the tough lower ends and any stems that are greater than ¼-inch in diameter. Toss the rabe with a light drizzle of olive oil and a sprinkle of salt and pepper. Rub the olive oil onto the leaves to make sure the rabe is lightly and evenly coated with oil. Set aside.