Is straying away from Keto food for one meal on occasion really that detrimental to the plan? I don't do Keto so I don't know, but I'd think an occasional indulgent meal is just fine as long as you don't go overboard with the calories.  Go out to Olive Garden once in a while and enjoy a couple slices of pizza! Just drink water instead of ordering soda and leave the bread there alone, and eat light salads for the rest of your food that day. Maybe it's not optimum nutritionally, but you can do that and still stay well below your daily calorie goal and lose weight.