Cook the pasta for 1 minute over what the package suggests for al dente. If it says to cook 8 - 9 minutes, cook it for 9. Otherwise, add 1 minute to the lowest number listed on package. Since this pasta salad is served at room temp or cold, you need to cook it just past al dente or it will be too chewy.
Meanwhile, whisk together the oil, vinegar, garlic, salt, and pepper in a large bowl. Add the frozen spinach and break it up so that it's loose, then toss to coat. The spinach will start to thaw when mixed with dressing and should be fine by the time the pasta is done. When the pasta is added, it should be completely thawed.
Drain and rinse pasta with cold water to stop cooking. Combine with spinach mixture and cheese. Toss until combined. Taste and adjust for seasoning, adding more salt if needed.
*Buy spinach that's loosely frozen in a bag. I buy Trader Joe's organic chopped spinach and use ½ a bag. If you use the frozen solid boxed spinach, you will need to thaw it out before using. If all you can find is a 10 ounce package, use all of it.**You can use crushed red pepper for more heat.If refrigerated, let it come to room temp before serving. You can drizzle with some additional extra virgin olive oil before serving.
Spinach and Cheese Pasta Salad https://www.thegeneticchef.com/spinach-and-cheese-pasta-salad/