First you need to work out which type of shade you have. It may sound daft but deep shade, which gets little or no sunlight at all, will prove difficult as a growing area. In contrast, an area which gets even a few hours of light a day, even if that is in the morning or evening, or dappled shade throughout the day, can provide enough light to grow some edibles.
You may be able to increase the light to the area by lifting the crowns of nearby trees or even by pruning back a few branches.
Leafy, green crops do not need much sunshine to thrive and in fact, salad leaves like lettuce, rocket, and spinach, as well as oriental greens, grow better in cooler weather. Too much summer heat causes them to bolt quickly and the leaves then taste bitter.
Other top shady performers are rhubarb, radish, Swiss chard, bok choy, kale, wasabi, the three-cornered leek, and perennial Welsh onions, as well as the full range of brassicas like cabbage, broccoli, and Brussels sprouts.
If your plot gets morning sun but plunges into afternoon shade, carrots and leeks will grow away happily.
Think hedgerow fruit for inspiration if you want to grow fruit in a shady corner. Blackcurrants, blackberries, gooseberries, raspberries, red and white currants, alpine strawberries, or the Japanese wineberry or American chokeberry will all be happy in partial shade. Even pears and culinary varieties of plum need only a few hours of sunshine a day to thrive.
Sunshine is important for ripening fruit and producing the sugars which make it taste sweet. So it follows that fruit grown in shade will taste less sweet, but you can still grow fruit in shadier areas to use in cooking or preserving where you can add natural sweeteners if required.
Some herbs can survive without Mediterranean climes with parsley, chives, sorrel, lovage, and horseradish all happy to grow in a partially shady spot. Mint, although you must keep it contained in a pot or it will spread everywhere, is perfectly happy in deep shade.
Do not let a lack of sunlight in your shady garden or allotment put you off enjoying the riches of growing your own produce.