Which beans are legal?
PecanBread recommends fresh lima beans first.
If you're looking for cooked:
Haricot Beans aka Navy Beans aka Green Beans
Lentils
Lima Beans
Navy Beans
Split Peas
Leaving black and kidney as more advanced.
Make sure to prepare them according to BTVC. Elaine said after you show some improvement (around month three).
Additional Bean info.