I also bought a supermarket pot of Mint a few years ago, not sure which supermarket.
I have a hanging basket in my front doorway, south facing, watered daily and fed once per week during late spring through late autumn and the mint is in a 'planter' (approx 36in/100cm x 12in/30cm x 12in/30cm deep) directly below. It has flurished every year and was a welcome place for one of my cats to 'sleep' during the cooler months between Autumn and Spring.
I am hoping for a better year for my Garlic this year. Last year was disastrous following 'The Beast from the East' and then the long hot dry summer. I was going to try to grow some oregano this year but I am too late now I think.
BAJ