The best local food is the food you grow yourself.
For city dwellers, the eco-niches available are limited only by imagination. If you have no land to cultivate, then container gardening is one of the best options. Inside or out, containers offer mobile planting options for decks, patios, rooftops, windowsills, etc.
I've often lived in rented houses with a backyard but the incentive to dig a garden is limited when you may have to leave all your work and plants to a new tenant the next year. My current container garden is mostly herbs and tomatoes. The tomatoes are a special luxury treat grown for taste, freshness, and eating out of hand, rather than a crop I can preserve as bottled sauce. The herbs I mostly dry and used over the remainder of the year for cooking.
The containers do not have to look pretty. Many of mine are plastic cat litter containers with a few holes punched in the bottom, or low-cost dollar store varieties. Each year I re-use them. Traditional clay pots are still the best choice though if you can afford them.
There are a couple of keys to successfully grown container plants. Pay daily attention to them. Containers dry out far more rapidly than a traditional garden and in the heat of our summers daily watering is not an uncommon need.
Research the plants you choose, either online or from books bought or borrowed from the library. Some plants prefer dry, sandy, well drained soil, and others like to live in moist soil with lots of fibrous humus. It's also important to know whether your plants are shade tolerant or need full sun. The advantage of containers is that you can move them around to find a micro-climate that they will thrive in.
Growing your own will give you a chance to taste and preserve native and heirloom varieties that never show up on the supermarket shelves. But the real reward comes from the amazing taste and pleasure of eating your own healthy organic produce that has no added food-miles.