Prep Time: 10 Min
– 1 1/2 c. water, divided, plus more for pasta – 3/4 c. raw cashews, divided – 2 tbsp. plus 1 1/4 tsp. kosher salt, divided – 16 oz. penne – 3 tbsp. extra-virgin olive oil, divided – 3 tsp. crushed red pepper flakes, divided – 1 small yellow onion, chopped – 4 cloves garlic, finely chopped – 6 tbsp. tomato paste – 1/4 c. sun-dried tomatoes, finely chopped – 1/4 c. fresh basil leaves, finely chopped, for serving
Cook Time: 1 hr 20 mins
Boil 1 cup water in a small pot. Add 1/2 cup cashews. Soak 1 hour.
Rinse soaked cashews. Blend 1/2 cup water and 1/8 teaspoon salt. Blend until smooth, then add to a small container (approximately 3/4 cup cashew cream).
Boil a large pot of salted water. Cook penne, stirring occasionally, until very al dente, 2–3 minutes less than package guidelines. Save pasta cooking liquid.
In a large, high-sided skillet, combine 1 tablespoon oil, 1/8 teaspoon red pepper flakes, 1/8 teaspoon salt, and 1/4 cup cashews. Toast 4–5 minutes, stirring often. Put away. Wipe skillet.
Heat remaining 2 tablespoons oil in skillet. Simmer onions, garlic, and 1/2 teaspoon salt for 5–7 minutes, tossing occasionally. Stir tomato paste, sun-dried tomatoes, and 1/4 teaspoon red pepper flakes 3–4 minutes.
Simmer 3/4 cup pasta liquid and cashew cream. Liquid pasta. 1/4 cup at a time until pasta is al dente and sauce glossy and coated, 2–3 minutes. Needs salt.
Distribute spaghetti. Grate leftover toasted cashews over spaghetti using a microplane. Add basil.