You don’t need an allotment or large garden to grow your own food. A patio can hold pots of herbs or hanging baskets with tomatoes. For a more established area try a raised bed like the VegTrug.
I’ve been using one of these for many years now and here are just a few vegetables that do really well: Beetroot, Carrots, Lettuce, Dwarf Peas, Radish, Spring Onions.
I erected mine by myself and it didn’t take long to complete. Using multi-purpose compost I filled it to the top and have since topped it up every year with just a couple of new bags of compost.
In the centre, grow Carrots, followed by Beetroots down one side of the carrots. Salads such as Lettuce are best suitable around the sides as their roots don’t take up much room. Maybe some Chives in one corner. There are so many combinations but the basic rules are, roots in the centre working out to plants which has shallower roots to the edge.
At one end I use it as a seed bed. With it being off-the-ground there is less pest damage so the seedlings get off to a flying start. So for me, it was worth the investment, plus, it saves on bending down and having back pain.