I reckon, even with rationing, food need not be dull. I grow all the traditional root crops and brassicas but also squashes and pumpkins, courgettes and sweetcorn, soft and hard fruit, aubergines, peppers, tomatoes. I freeze the surplus, I will eat our last corncob for lunch tomorrow. Surplus crops can also be made into jams, and chutneys. herbs can be grown on windowsills.
We could have, what in France, were smallholders markets, where people gathered with surplus from their gardens - 2 cauliflowers, a mass of spinach, 1 doz eggs, a bunch of rhubarb and some jars of home made jam to sell. The mainly elderly ladies would sit on chairs with their produce on small tables in front of them, chatting away and often knitting. When DGD was small I bought some knitted dolls clothes off one of these stalls.