First get your rice started, either in a rice cooker or on the stovetop.
Next, start the pajeori scallion salad. Cut the scallions into 2-inch lengths and julienne them very thinly. Transfer the scallions to a bowl of ice water as you cut them. This will help them curl nicely and also take some of the edge off the scallion flavor. When all the scallions are cut, set aside while you prepare the other ingredients.
Slice the mushrooms into ¼-inch thick, 2-inch pieces. If you cut the mushrooms crosswise, you’ll go against the grain and the pieces will be more tender. If you cut the mushrooms with the grain lengthwise, they will have more of a bite, kind of like a piece of pork belly would.
Mix 2 tablespoons of oil, the liquid smoke, sesame oil, sugar, and salt. Whisk to combine and emulsify. Brush the mushrooms with the marinade.
Heat a skillet or nonstick pan with enough oil to coat the bottom over medium-high heat. Add the mushrooms in a single layer and cook until golden on one side. Flip and brown on the other side. When you flip the mushrooms, add the onions, peppers, and garlic into the pan to brown also.
While that’s happening, finish your scallion salad. Drain the scallions and run them through a salad spinner or pat dry on a kitchen towel. Toss with the soy sauce, sugar, sesame oil, gochugaru, and sesame seeds until well combined.
When everything’s cooked to your liking, assemble your vegan Korean BBQ bowl. Add a base of rice to the bowl, a handful or two of lettuce, the mushrooms and veggies, kimchi, and a scoop of ssamjang paste. Top with the pajeori scallion salad to taste. Mix everything together like you would with a bibimbap and enjoy!