Heat half of the oil in a large skillet over medium-high heat. Once oil is shimmering, add the potato noodles and season with chili powder, garlic powder, salt, and pepper. Cook until wilted and browned, about 10 minutes. When done, set aside on a plate and tint with foil to keep warm.Meanwhile, prepare the meat mixture. First, add the mushrooms to a food processor and pulse until finely chopped. Set aside in a bowl and then add in the cauliflower and pulse until ground to meat-size crumbles, do not overpulse or else it would be like couscous. Transfer to the bowl with the mushrooms and then add in the walnuts and pulse until ground, but not too much so that it’s a powder. Transfer to the bowl with the pulsed vegetables.Once potatoes are done cooking, heat the remaining oil in the same skillet used to cook the potatoes back over medium-high heat. Once oil is shimmering, add the garlic and onion and cook for 3 minutes or until softened.Add the tomato paste and stir well to coat the mixture. Add in the pulsed vegetables (cauliflower, mushrooms) and pulsed walnuts. Season with paprika, cayenne, and salt and pepper. Stir well and then add the barbecue sauce, liquid smoke, and soy sauce. Stir again and let cook until browned and liquid has absorbed, about 5-10 minutes.Meanwhile, prepare the dressing: add all the ingredients to a bowl and whisk well to combine. Taste and adjust to your preference.Prepare the bowls: divide the potato noodles and hamburger meat mixture into four bowls. Top with lettuce, shredded cheese (if desired), pickles, and tomatoes.Drizzle with dressing and serve.