I bike to work, but still make a lot of soups. The trick for me is to have really high quality plastic-ware that will not leak, and try to keep it upright in your bag anyway (I literally just hold a plastic bag from one hand while biking, but I only bike 1.5 miles).
My staples are split pea soup and potato soup. Both are super healthy with a lot of veggies and very filling.
Split pea soup: 1 bag split peas, chopped carrots, celery, onion, 1/2 lb ham. spices: thyme, pepper. Cook on low in crockpot for 10 hours.
Potato soup: simmer 6 chopped potatoes, celery, carrots, onion in a pressure cooker, add 2 qt chicken stock, paprika, caraway seeds, dill seeds, margoram... cook for 15 minutes once the pressure thingy starts rocking back and forth. Depressurize it (using water if your pressure cooker supports), 1.5 cups skim milk powder in a blender with some juice from the soup, then re-mix. it makes it creamy and thick without the unhealthiness of cream.
I think both are super delicious. I usually also bring a pb&j or ham sandwich on whole wheat for a mid-morning snack. Healthy, filling, inexpensive, mustachian!