McCain is , by far, the brand leader in the UK for frozen chips (and American style fries). We usually have a bag of their oven chips in the freezer.
Many years back, we were visiting rural northern France (following where my grandfather had served in the Great War). It’s a large potato growing area. We were having a drink in the hotel bar and got chatting to the only other customer, a fellow Briton. Turns out he worked for McCain’s procurement department and was on a quality control visit to the area to watch over the harvest, prior to shipment to the UK.
It is so omnipresent here that it rather surprised me, when I looked just now, to find that the parent company is Canadian