Looking for meals that can easily be made vegetarian

Hello! I’m a meat eater along with 2 of my roommates. I am the primary cook and I prefer meat in most if not all meals. One of my roommates is having their partner move in soon, who is a vegetarian. Does anyone have suggestions for meals I can make that I can add the meat separately? I’m really struggling with this because I grew up in a family where meat is the focus and you add sides to bulk it up. Any help is appreciated!