Press the saute button and let inner pot get hot. Add olive oil and diced onion and saute for 2-3 minutes. Add ground sausage. Continue to saute, breaking up the sausage, until the sausage is crumbled into small pieces and slightly browned, approximately 2-3 more minutes. The sausage does not need to be fully cooked at this point. Add garlic and saute 1 more minute.