Add everything to a food processor and blend into a thick paste. Stop and scrape down the sides if needed. Blend into your desired consistency. For a thinner sauce, add more olive oil as needed. Set aside.
Bring a large pot of salted water to a boil. Cook pasta until al dente according to packet instructions. Before draining, carefully reserve about 1 cup of the pasta water (240ml) and set aside.
Add the olive oil to a large pan and warm over a medium heat. When the oil is shimmering add the garlic and chili flakes. Sauté 1-2 minutes until fragrant.
Add the kale to the pan. Stir and cook another few minutes to soften the leaves. Add water to the pan then cover with a fitted lid and cook about 3 minutes to steam and soften the kale. The kale should become noticeably darker and softer.
Reduce to a low heat. Add the cooked pasta to the pan along with the reserved water and red pesto sauce. Toss pasta until fully combined.
Taste and season with more salt, pepper, chili flakes etc as you see fit.
Cool leftovers to room temperature then pack up in an airtight container and keep refrigerated for up to 4 days
