Cook the pasta per package directions.
Heat a pot of water to boiling point. Add the turnip greens and let them cook for a minute. Turn off the heat, drain and rinse the greens.
Add the greens to a food processor along with the walnuts, garlic, red pepper flakes, olive oil and salt. Blitz into a fine paste.
Place the chopped turnips on a baking sheet sprayed with oil. Season with salt and pepper and roast in a preheated 425-degree oven about 30 minutes or until golden and tender.
Heat the remaining 1 tsp of extra virgin olive oil in a saucepan and roast the mushrooms over medium-high heat until golden and tender.
In a large bowl, mix the pasta, pesto, roasted turnips and mushrooms, and capers. Add more salt or ground black pepper to taste.