Combine the onion, bell pepper, cumin, garlic powder, chili powder, beans, tomato sauce, fire-roasted tomatoes, water, salt (taste the mixture prior to adding the quinoa, adding salt to taste), and quinoa to a 6-quart slow cooker, stirring to combine. Cover and cook on high for 3 hours or on low for 6 hours, or until the quinoa is cooked through.
Uncover and stir in the green chilies and lime juice. Taste and add additional salt or lime juice if you like.
Serve with any toppings you like such as avocado, chopped green onions, cilantro, grated cheese, sour cream, hot sauce, or sliced limes. If you want crunch, go for crushed corn chips and chopped white onion.
Pull aside a portion prior to adding the green chilis if you're serving someone sensitive to heat.Top with avocado and chopped green onions, or sprinkle with cheese and dollop with sour cream.Since the consistency of this dish is decidedly creamy, feel free to top with crushed corn chips or chopped white onion to add crunch.