For the pesto:
1 cup fresh basil leaves
2 Tbsp roughly chopped cashews
1 large clove of garlic, roughly chopped
1 tsp black pepper
1/4 tsp kosher salt
4 Tbsp extra virgin olive oil, divided
2 Tbsp grated Parmigiano-Reggiano cheese
For the squash:
1 2-lb spaghetti squash
3 Tbsp cashews
15-oz can cannellini beans, drained and rinsed
1/4 cup grated Parmigiano-Reggiano cheese
In a food processor fitted with a metal blade, chop the basil, cashews and garlic to a coarse mixture. Add the pepper, salt and oil, and process until smooth. Then add the 2 tablespoons of cheese, and pulse the mixer a few times to incorporate everything. Transfer the pesto to a small bowl. Press a piece of plastic wrap directly on the surface of the pesto, and refrigerate. (You can make pesto far ahead, and refrigerate or freeze it.)
Cook the spaghetti squash in a pressure cooker (fast) or the oven (not quite as fast).
Pressure cooker method: Trim off the stem end of the squash, and cut the squash in half lengthwise. With a spoon, scoop out the seeds and stringy bits. Place the two halves in the pressure cooker and add 1 cup of water. Cook on High Pressure for 8 minutes, and use the Quick Release method to release pressure (follow the instructions that came with your pressure cooker). When the pressure valve drops, open the lid. Use tongs to remove the squash halves to a platter, and let them cool while you prep the rest of the dish. Then, use a fork to scrape the "spaghetti" out of the skin.
Oven roasting method: Preheat the oven to 375°F. Cut the squash in half lengthwise, and scoop out the seeds. Place the two halves cut side up on a rimmed baking sheet. Drizzle each half with extra virgin olive oil. Bake for 45 minutes, or until the squash is tender when pierced with a knife. Remove from the oven and set aside to cool while you make the rest of the dish; then, use a fork to scrape the "spaghetti" out of the skin.
While the squash is cooking, toast the cashews in a dry frying pan over low heat for 3-4 minutes, until the nuts are lightly browned. Remove from the stove and set aside.
Place the squash strands in a large mixing bowl. Add the beans, then the pesto. Mix gently with a rubber spatula; try not to break up the beans (too much -- it's impossible not to break a few of them). Stir in the cashews and cheese, and mix everything together.
Serve hot or at room temperature.