In a skillet, heat the olive oil over medium-high heat.
Add the squash, cherry tomatoes, mushrooms, and garlic.
Season with the Italian seasoning, garlic powder, salt and pepper.
Cook, stirring frequently until the vegetables are tender, about 10 minutes.
If the cherry tomatoes have not popped, cover and continue cooking until they do.
Turn off the heat and serve warm. Season with more salt and pepper, if desired.
Season with salt and pepper and serve warm or at room temperature.