Heat olive oil in a pan over medium heat. Toss the sweet potato pieces in the hot oil, sprinkle with salt & pepper, and cook until golden brown (10-15 min).Stir occasionally.
Add chopped onion into the pan and cook for about 5 minutes until it is soft and tender. Continue stirring.
Add the kielbasa, cut into 1-inch pieces, to the pan. Cook for about 5 min to heat it through. Continue stirring occasionally.
Add the summer (yellow) squash to the pan. Add about a tablespoon of water and cover the pan to allow the squash to steam. Keep covered until squash is tender. Remove cover and let cook for another few minutes. Enjoy!