Preheat oven to 350° F. Choose your pan/baking dishes (See Equipment section above Ingredients for size and shape options). If you're using a pan/dish that sticks, grease with oil, or line with parchment paper.
Measure water, then sprinkle gelatin over and into water. Whisk a few times. Set aside for 10 minutes to thicken while you measure the flour and the oven preheats.
Pour the green banana flour, tiger nut flour and optional coconut flour into a medium-large mixing bowl. Add the baking soda and sea salt, and stir to combine.
To the gelatin mixture, add milk (make sure it's not cold), oil and lemon juice/vinegar. Smash together with a fork, and stir, so there is no longer a soft clump of gelatin. (Milk that is too cold will not allow the gelatin to soften and smash in evenly. Be sure your milk isn't cold. If for any reason your gelatin is too hard to smash in, warm the liquid ingredients gently until they're all smooth, then add to the dry ingredients and proceed.)
Pour the wet ingredients into the dry, and mix well to combine. I use handheld electric beaters. Beat for a total of about 50 seconds: after the batter comes together, go another 15 to 20 seconds. It will look slightly whipped. I start at the lowest speed, and then increase the speed to medium the final 10 seconds. (Note: If your coconut milk is on the warmer side, your dough will be thinner than in the next two photos, more like a thick batter. So you won't be able to shape it. But, it will still bake up perfectly.)
Scrape dough into prepared baking pan/dishes, and shape so the dough is smooth and slightly mounded on the top. You may also use your hands to shape the dough.
Bake in preheated oven. If you've divided the dough into 4 pans or dishes, bake about 20 to 24 minutes. Tops will be mounded and cracked. Toothpick inserted into the center will come out dry or with a few moist crumbs adhering. For larger single loaf, bake time will be about 40 minutes.
Cool in pan on rack for 20 minutes, then unmold and finish cooling on rack.
Slice any direction you like, eat as-is, or toast first. Eat as bread or toast, as a side dish or for sandwiches.