Prep time - 15 minutes Cook time - 15 minutes
Cut squash into 1/4" thick slices.
Dice the onions.
Heat olive oil over medium heat in the large skillet, about 1 minute.
Add onions and garlic; saute in the hot oil until tender, 2 to 3 minutes. Add zucchini and squash; season with Italian seasoning, salt, and pepper.
Saute until squash is tender, 8 to 12 minutes.