One of my favorite pasta toppings is pesto! I’ve done some experimenting with recipes in the past and recently made a new one with almonds, spinach, olive oil, and parmesan cheese. Yum! I have really only made basic pesto (basil, pine nuts, olive oil) a couple times because pine nuts are so spendy, but these ingredients are fairly inexpensive, especially if you get the almonds in bulk. You can also use a different oil if you are trying to save money, but the taste will be different than with olive oil.
In addition to the pesto, I added sliced sausage, peas, yellow onion, mushrooms, and green bell pepper to increase the nutrient content, my favorite thing to do when I cook!