Sour cream
Son: "What did you make for dinner, Momma?"
Me: "Burritos. Well, burrito bowls. It has rice, beans, corn, some spices, cheese, and sour cream."
Son: "No! I don't like it!"
Me: "Yes, you do. You've had it before, and you like it just fine. Sit down."
Son: *starts to get weepy-sniffly voice* "I can't eat it! I don't like sour! I only like sweet!"
Me: *tries very hard not to snicker* "It doesn't really taste sour. That's just what it's called."
In the end, I ended up having him come into the kitchen with me, take a taste of the sour cream by itself, and then he was fine with it and ate the burrito without a problem.