Val's Easy and Amazing Yellow Squash with Tomatoes and Parmesan (Video)

+ 1 tsp. olive oil (or slightly more, depending on your pan)

yellow or white onion, diced

garlic cloves, finely minced (or to taste)

medium or 3 small yellow summer squash

cherry or grape tomato halves

salt and fresh gorund black pepper

finely grated Parmesan cheese, plus more for serving if desired