Char poblano pepper under oven broiler for 3-4 minutes per side until skin is black and blistered. Chop entire pepper, seeds and all, once it has cooled enough to handle and set aside.**
Heat olive oil in a Dutch oven or large stock pot over medium-high heat. Add onion and bell pepper and cook until softened, about 3-5 minutes. Add garlic and cook until fragrant, about a minute.
Add ground meat and cook until almost cooked through, about 3-5 minutes. Season with salt, black pepper, chili powder, chipotle pepper, garlic powder, paprika, cumin, ground mustard, and cayenne. Stir to combine.
Add tomato paste and cook while stirring for 2-3 minutes. Add crushed tomatoes, diced tomatoes, poblano peppers, brown sugar, espresso powder, and balsamic vinegar and stir to combine. If using, add vegetable or beef broth at this time. Reduce heat and simmer, uncovered, stirring occasionally for 15-20 minutes. Add additional salt and pepper to taste if desired.
Add beans and stir to combine with the other ingredients. Continue to simmer for and additional 10-15 minutes.
Serve immediately and top with shredded cheddar cheese, chopped jalapeno and sliced green onions if desired.