Make the pasta:Bring a pot of generously salted water to a boil, and cook your pasta according to package directions. Drain it, reserving 1/2 cup of the cooking water. Do not rinse.spinach pesto:Add the cashews to food processor and pulse a few times until crumbled.Add the spinach, coriander leaves ,lemon juice, salt, garlic,and pepper, and continue to pulse.Add olive oil to this dip and mix well more lemon juice to taste if desired, and set aside.spinach pesto pasta:In a large pan, heat butter over medium heat. Add the onion or shallot and a sprinkle of salt. Continue to cook, stirring occasionally, until the onion is softened and browning slightly. (Note: to save time, you can begin this step while the pasta is still cooking).Add the garlic and cook for just about 60 seconds more, i occasionally, until the garlic is fragrant.Add the cooked pasta, r, and pesto and fold everything together gently. Reduce the heat to medium-low and cook, stirring frequently, until the sauce has thickened slightly and clings to the pasta,.Ready to eat....no need of any sauce taste is yum.....