Favorite Bun Replacement

I have yet to find a bun replacement but I plan on giving these a go soon! https://www.beachbodyondemand.com/blog/cloud-bread-recipe

Do you have a favorite replacement? I’ve seen various veggie slices used and low carb recipes but so far this one looks the most promising to me. I’m more inclined to go without a bun or do a lettuce wrap until I find the right one.