Pesto cream sauce is a creamy, buttery, nutty wondersauce, elevated by earthy bite from basil and garlic. Made with milk, it's light enough to serve up in summertime and hearty enough to fill up on. You can totally take the easy way and used jarred pesto. Use a wide, flat noodle like fettuccine, and don't forget to save your pasta water - it's a must for this (and most) pasta sauces.
Heat a large pot of water until boiling, then season with the salt. Cook the pasta according to package directions. Reserve 2 cups pasta water, then drain.
Place the pot back over a medium flame. Add 2 tbsp butter and heat until it melts then foams. Sprinkle the flour over the butter and whisk until the flour turns lightly golden brown, 1-2 minutes.
Pour in one cup pasta cooking water and one cup milk. Whisk and simmer until the mixture thickens slightly, about 5 minutes. Add the parmesan cheese gradually, a few tablespoons at a time, whisking until smooth; repeat until all of the cheese has been added and the sauce is thick.
Stir the pesto into the creamy pasta sauce; start with ¼ cup, adding more to preference.
Add the cooked pasta to the sauce and toss; add more pasta water if the sauce is too thick. Garnish with fresh basil and cracked black pepper and serve immediately.
Notes
Use good quality jarred pesto sauce, made with real food ingredients.
Storage: store leftovers in a sealed container in the fridge for up to 4 days. Reheat, adding a bit of leftover pasta water to help loosen the sauce (it will firm up in the fridge).
Store leftover pasta water in an airtight container (like a mason jar) in the fridge.
Freezer instructions: double the sauce, and store half in an airtight container in the fridge. I like to put sauces into gallon zip lock bags, then freeze flat for easy storage.