The Slow Food Movement simply emphasizes taking time to find good quality ingredients and learning to prepare them well. This goes from fresh and interesting produce such as a range of greens to artisinal cheeses and breads. I don't know how left wing it is since it mainly protests against the bland sameness of how many people approach food. It proposes grocery shopping as a kind of daily foraging in the markets in the sense of Alice Waters's Chez Parnisse rather than running into the super-mega-grocerystore once a week and filling up the grocery cart.

Naturally, the question of genetic-modification is a concern but then so is the narrowing bandwidth of strains of lettuce.