Add 1 1/2 tablespoons oil to a large heavy-bottomed pot over medium heat. Add onions and garlic and sauté until softened (about 4 to 5 minutes). Add remaining oil, then mushrooms. Sauté until softened (about another 5 minutes).
Stir in the spices (oregano, chili powder, paprika, cayenne pepper, and cumin), and stir until fragrant (about 1 to 2 minutes).
Stir in the tomato paste and cook about 4 to 5 minutes, or until a darker red color and scorching on the bottom.
Pour in remaining ingredients, starting with 1 cup bean liquid, and stir. Add in an extra cup of bean liquid if you prefer a soupier chili. Bring to a boil, then reduce heat to a simmer for 30 minutes.
Top with diced avocado, chopped yellow onion, fresh cilantro, dairy-free sour cream, etc., and serve with cornbread.