Drain and rinse soaked beans.
Add beans to boiling water, and cook for only half the time (varies by bean type) you would if you were cooking them to eat directly. You want them to be al dente (not quite fully cooked).
If using rice (not barley), follow normal cooking instructions, except use equal parts rice to water to make the rice 'dry'. (This is important to help absorb moisture from beans.)
If making barley (not rice), drain barley from soaking water then add bring 2 cups water to a boil in a saucepan. Add barley and cook until it relatively dry (but not so dry that it sticks to the bottom of the pot and burns. Stir it frequently to avoid burning it.
Drain cooked beans, let cool enough to handle them, then rub beans together to de-hull them. Pat dry with a dish towel.
Transfer beans to a large mixing bowl. Mash lightly. Add cooked rice or barley if using.
Let mixture come down to body temperature (100°F/38°C), then add tempeh starter and mix thoroughly.
Punch holes every 1/2 to 3/4 inch (1 to 2cm) into both sides of either two 1-quart/liter or one 1‐gallon/4 liter zip‐top bag (you are creating air holes for the tempeh to breathe.)
Add mixture to bag(s).
If using banana leaves, add a square or rectangular portion of the mixture about 1 inch thick (not thicker than 1 1/4") to the center of the leaf. Fold the sides in (like you are wrapping a gift). Fold the ends in and use toothpicks to secure the ends of the "package".
If using banana leaves, use a sharp knife to cut small (1/4 inch long) slits all on both sides and along the sides of each package.