Well, my opinion is that there's no reason you have to eat the same thing. Maybe I'm a bit of a hardass (

) but if someone is a picky eater, then I think it's kind of their responsibility to handle their own food.
That said, there are plenty of
vegetarian meals that you can make and then he can add his own processed meat or whatever. Or you can fix meals for you, and he can eat the sides and fix his own meat of whatever kind he wants.
My housemate doesn't really like fish, but I love it and eat it 2x a week or more - so when I do I just fix a full meal (fish, veggies, sides, etc.) and he throws a burger patty on the stove or grill or whatever for him. Then he'll eat whatever veggies I've prepared with his burger or chicken.