Place the walnuts in a small skillet and cook over medium heat, stirring frequently, until toasted and fragrant. Place the walnuts in a food processor. Add the basil, garlic and parmesan to the food processor. Pulse a few times to chop and combine. With the food processor on, stream in the olive oil until all of the ingredients come together. Season to taste with salt.

Place the white wine vinegar and olive oil in a jar with a tight fitting lid. Add in half of the pesto and season with salt and pepper. Screw on the lid and shake vigorously to combine.

Bring a large pot of salted water to a boil. Add the pasta and cook until al dente. Drain.

Place the pasta in a large bowl and add half of the pesto. (The other half goes into the dressing.) Stir to coat the pasta with the pesto.

In a large bowl, combine the romaine, ham and tomatoes. Stir in the pasta. Add the dressing and toss to coat. Serve topped with shaved parmesan.