Eating the same lunch 2-3 days in a row is not boring to my partner as long as we don't cook the same big batch recipe two-three times a month, and I switch between two different tastes on my meal replacement.

Honestly, lunch for me could be oatmeal porridge for all eternity. It's lunch, doesn't have to be a gourmet dinner. And on those days where you really don't feel like that lunch box, then you could take one from the freezer or just buy something.