That happens to me here and there. And like you, it is associated with what I eat. It has come on and I’ve been annoyed for days with it. I was on an under packed plane and as I was leaving I heard the flight attendants saying that they smelled something burning. That’s not the first time that I’ve heard someone make a comment. I felt that maybe my stomach acid was too strong and was burning something. I’ve made an effort to overeat to utilize the acid and it dulls then comes back. The other day, I took a B complex vitamin before going to bed and the smoke scent went away! Something similar happened before... I ate really spicy lamb... which has B vitamins in it and my burnt smell went away. That was a month ago. Maybe it’s a B vitamin deficiency. You never know when you are deficient in vitamins and minerals until you get sick.