Place all the beans in one container, fill with water at least 2 inches higher than the beans, and soak overnight for at least 12 hours, preferably 18-24.
The following day, strain and place in a new pot with the halved garlic clove, bay leaf, and soy sauce. Add enough water to cover the beans thoroughly, again at least 2 inches above and bring to a boil on high heat.
Once boiling, turn the heat down to medium and simmer for around 1 hour or until beans become tender; allow for liquid in the pot to cook down until it doesn't cover the beans at all and there is a thin layer at the bottom of the pot.
While the beans cook, lightly saute the veggies. Once cooked, remove the veggies from heat and allow them to cool.
Once cooled, add the spices to the veggies and marinate until the beans are cooked.
When the beans are done cooking, and the majority of liquid cooked off, add to a separate bowl and roughly mash beans up using a wooden spoon/ pestle. You don't want it to be a paste, or the texture will be too smooth for burgers.
Mix the seasoned veggies and flaxseed meal to the mashed beans until evenly distributed.
Add the ¼ cup of garam flour at a time and thoroughly mix. This is being used as a binder, so you may not need all of it. When the burgers begin sticking to themselves without falling apart, stop adding. If necessary, add all of the garam flour. If you still think the mixture is too wet and not holding together, add additional flour as necessary.
Divide and shape the bean burger mixture into 130-135 gram-patties, which will result in 14 burgers.
Freeze or use right away. I recommend pan-frying them to get a nice firm layer, then finishing off on the grill. If you are solely cooking them on the grill, allow for them to cook on each side until completely hard before flipping to avoid burgers from breaking apart.
Notes
This is one of those dishes that buying in bulk helps. Many of the ingredients last for months and longer when stored in airtight containers. If you don't have garam masala, you can use a mixture of 1 teaspoon of ground cumin, ground cinnamon, mixed with 1 1/2 teaspoon of ground coriander, cardamom, black pepper, and 3/4 teaspoon of ground cinnamon, and 1/2 teaspoon of ground cloves as many of those spices are best to replicate a typical garam masala.