We had spicy bean burgers with salad. Our favoured 'Good life' burgers used to be everywhere, but only seem to be in a couple of shops now
Ollie, there are a number of burger recipes for vegetarians/vegans online. My wife has made them before, but they are made primarily with black beans. You can put onion, garlic, or whatever seasoning you like into the mix, and they come out pretty good!