The day before or first thing, slice two red onions as thin as possible in semi circles. Combine in non-reactive bowl with the salt, lemon juice, and sumac. Mix periodically. Keep in the fridge with a tight lid.
Dice the other two onions and pre-heat a large pot on medium-low heat with the olive oil. Saute the onion until translucent. Add the garlic, oregano, and cumin.
While cooking the aromatics, prepare the herbs: the fresh epazote and dried hoja santa. Rinse the epazote and chiffon like basil, add to the pot of aromatics. We buy large packs of epazote at a latin grocer, wash and freeze in small bags. Take the dried hoja santa and carefully rinse, then briefly set on your cutting board. Take one can of beans, drain (rinse if you prefer), and add half the can to the pot. Add a few tablespoons of water to the remaining half can of beans, crumble in your hoja santa, picking around the stiff stems/large veins. Add your chipotles. One of my best discoveries has been that my stick blender fits in a can. Blend the can of flavor allllll together! Add to pot and stir.
Open and drain your remaining cans of black beans and mix in. Add the two teaspoons of salt, mix, taste, and add more salt to taste. Turn down to low and stir every 4-5 minutes while you prepare the cheater Chile Relleno.
I hate frying, so I prefer do what I've dubbed the "cheater" Chile Rellano. Turn the oven top broiler on high and line a rimmed sheet pan with foil. Carefully cut a slit down one thin side of each Poblano chile, so that it lays on either flatter side without the slit facing down. Clean out the seeds and as much of the veins as easily reached. Sprinkle inside with cumin and salt. Cut cheese into 6 equal slices and stuff in the peppers. Rub outsides with 1 tablespoon olive oil and place under broiler. When the first side just starts to get black spots, flip with tongs and broil second side.
Chop the red cabbage and prepare your avocado. Grab your cooked rice, pickled onion, and condiments. Slice up the cheater Chile Relleno once cool enough to handle. Assemble your bowls!!