In a nonstick pan, dry-toast the walnuts on medium heat, tossing and flipping them for about four minutes. Remove from heat and place in the bowl of a food processor. Add the oats, tomato paste, chipotle pepper, adobo sauce, sea and garlic salt, mustard, worchestershire sauce, and liquid smoke. Process until pasty. A few chunks are fine. Add 1/2 the black beans, and 1/2 the rice. Pulse until the mixture comes together, scraping down as needed. Set aside.
Heat the coconut oil in a pan on medium. When shimmering, add the diced onion and cook on medium for about three minutes. A bit of charring is okay. Remove from heat and place in a large mixing bowl. Add the remaining 1/2 of the black beans and rice to the mixing bowl. Into the large mixing bowl, add the processed bean/spice mixture. Using your hands, mix throughly squeezing and pushing the mixture together.
Use a 1/2 cup (130g) scoop (this yields 5 patties) or 1/3 cup (82g) scoop (this yields 8 patties) to portion the patties. Roll them into a ball. Using the back of a metal measuring cup, press each ball into a patty using gentle pressure about 1/4"- 1/2" (.6 - 1.2 cm) thick.
Place the patties flat on a parchment lined sheet pan in refrigerator for at least one hour. If freezing, slide the pan in the freezer for one hour then stack them between pieces of parchment paper and into a freezer bag for longer storage. Now is a good time to get the boozy onions going (see below).
Preheat the oven to 200F (95C) and line a sheet-pan with parchment paper. Place the pan in the oven. This will keep the patties warm after they're cooked.
Add two to three Tbs of coconut oil to a cast iron skillet on medium heat. Heat until shimmering. Add three patties. Be sure to give them plenty of room. Cook for 3 1/2 - 4 minutes on each side, being careful when flipping the patty. Slide the patty on the parchment lined sheet pan in the oven. Sprinkle with sea salt. Finish cooking the remaining patties adding more oil as needed.**