In a small bowl, combine chili powder, ground cumin, sweet smoked paprika, brown sugar, cayenne pepper, onion powder, garlic powder, dried oregano, mustard powder, kosher salt, and ground pepper. Mix thoroughly to create a vibrant, aromatic spice blend.

In a microwave-safe bowl, combine olive oil, diced yellow onion, chopped celery, minced garlic, and your prepared spice mix. Cover and microwave on high for 4 minutes until softened.

Transfer the sautéed vegetable and spice mixture into your slow cooker, evenly distributing across the bottom.

In a blender, combine two cans of drained Great Northern beans with low sodium chicken broth, blending until smooth. Pour this blended mixture into the slow cooker.

Add the remaining drained beans, fire-roasted canned tomatoes, diced green chiles, and boneless skinless chicken thighs into the slow cooker. Mix gently.

Cover the slow cooker and set to low heat, cooking for 6 to 8 hours until the chicken easily shreds with a fork.

If desired, stir in Neufchâtel cheese during the last 30 minutes of cooking for a creamy texture.

Serve hot, garnished with fresh cilantro, lime wedges, shredded cheese, and tortilla chips.