I have never really understood the combination of moules et frites. I quite like fries and I love mussels but the two don't really work together for me. I'd prefer some nice bread to dip in the sauce.
A pub I was in recently offered chips with their potato pie. Now I'm more than happy to double carb but chips with a sliced potato pie?
Mac and cheese as a side confuses me too. I love macaroni cheese/mac and cheese but it doesn't seem to work as a side dish to me. Perhaps I've been missing out all these years.
Which food combinations confuse or disgust you?