To begin, bring a large pot that is 2/3 of the way full with water (water, which contains ½ tsp. salt and 1 tsp. olive oil) to a boil over medium-high heat. Add in the pasta and cook according to package directions or 5-7 minutes until al dente. When the pasta is done, drain in a colander.
Meanwhile, place a large skillet over medium heat. Add in 1-2 tbsp. olive oil and allow it to heat up, then add in the onion and garlic. Sauté for 3-4 minutes or until the onion is translucent and tender and the garlic fragrant.
Next, add in the eggplant, bell pepper, along with the zucchini, yellow squash, and mushrooms (of using), and sauté for 5-7 minutes or until the vegetables are fork-tender.
