Bucatini with Winter Pesto and Sweet Potatoes

INGREDIENTS
YIELDS: 4 SERVINGS
1 large sweet potato, peeled and cubed
1 medium red onion, cut into wedges
1/3 c. plus 2 tablespoons olive oil, divided
Kosher salt and freshly ground black pepper
4 c. torn kale, collards, or mustard greens
1/2 c. fresh flat-leaf parsley
2 oz. grated Parmesan cheese (about 1/2 cup), plus more for serving
1 clove garlic
2 tsp. lemon zest, plus 1.5 tablespoons lemon juice
12 oz. bucatini
toasted pine nuts, for serving

Source: https://www.countryliving.com/food-drinks/recipes/a41068/bucatini-with-winter-pesto-and-sweet-potatoes/