Break the sausages into small pieces. Heat a cast-iron skillet to medium, brush with ½ teaspoon of olive oil and cook 1 to 2 minutes or until well-browned. Remove and set aside.
Trim ½ inch off the ends of the broccoli rabe. Prepare a large pot of salted boiling water. Drop the broccoli rabe into the boiling water and boil for 2 minutes. Scoop out the broccoli rabe, reserving the boiling water. Drain and place onto a clean kitchen towel. Pat dry and chop into 1-inch pieces.
Bring the pot of water back to a boil, add more salt, and cook the pasta according to package directions or until al dente. Reserve ½ cup of the starchy pasta water.
When the pasta has about a minute left, heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the garlic and broccoli rabe and cook for 30 seconds. Add the wine, cook for 30 seconds, then use a slotted spoon to scoop the pasta directly from the pasta pot into the skillet.
Add the reserved pasta water, cheese, lemon juice, zest, red pepper flakes, ½ teaspoon salt, and freshly ground pepper and stir to combine. Stir in the cooked sausage, caramelized onions, sun-dried tomatoes, and top with the pine nuts. Season to taste and serve.