6. Start the Chili Base
In a large Dutch oven set over medium-high heat, warm the remaining 2 tablespoons of vegetable oil until it starts to shimmer. Add the onion, season with salt, and cook, stirring frequently, until softened, 5 to 10 minutes. Add the celery and poblano chili, season with salt, and cook, stirring frequently, until tender, 5 to 10 minutes. Lower the heat to medium, add the garlic, and cook, stirring constantly, until softened, about 1 minute. Add the mushroom and walnut mixture and stir to combine. Add the tomato paste, chili powder, smoked paprika, dry mustard, and cumin and cook, stirring constantly, until the tomato paste and spices are toasted, about 2 minutes.
Add the pickled jalapeño juice and cook, stirring to scrape up browned bits, for 1 minute. Add the mushroom broth, tomatoes, pinto beans, black beans, soy sauce, and liquid smoke (if using) and stir to combine.