We just finished celebrating Ian 's birthday . Karl baked a huge mushroom lasagna and made creamed spinach and carrots vichy , plus we had a huge salad . Everyone was stuffed , and then we brought out the gingerbread cake with cream cheese frosting . It was all wonderful .

Give answer the following question using evidence from the above passage: What may be the reason Karl made the kind of food that he did ?
Ian is a vegetarian .