Instructions

• Heat the water in a small pot, over high heat, until boiling, then add ⅔ of the cashews and boil for 5 minutes. Then drain and transfer the cashews to a blender and add 4.2 fl oz (120 ml) of the cooking water and ⅛ teaspoon of salt. Blend until smooth, then set aside.
• Cook the penne pasta according to instructions on packaging. Then drain and reserve 12.7 fl oz (360 ml) of the pasta cooking water.
• Meanwhile, in a large, high-sided skillet, combine 1 tablespoon of olive oil, with ⅛ teaspoon of red pepper flakes, ⅛ teaspoon of salt, and remaining whole cashews. Toast the nuts over a low heat for 4-5 minutes, tossing frequently, until fragrant. Transfer to a small bowl and set aside.
• In the same skillet, heat the remaining 2 tablespoons of olive oil. Add the onion, garlic, and ½ teaspoon of salt and cook for 5-7 minutes, stirring occasionally, until the onions have softened. Now add the tomato paste, sun-dried tomatoes, remaining ¼ teaspoon of red pepper flakes and cook for 3-4 minutes, stirring constantly, until the paste darkens and starts to stick to the bottom of the pot.
• Whisk in the cashew cream and 6.3 fl oz (180 ml) of the reserved pasta cooking water until combined, then bring to a simmer over a medium-high heat. Add the pasta and cook for 2-3 minutes, tossing constantly, adding a little more pasta cooking liquid as required until the sauce is glossy and coats the pasta. Season with ½ teaspoon of salt.
• Divide the pasta between 4 bowls, top with freshly chopped basil and serve immediately.