Dice the onion, mince the garlic, and dice the jalapeño (if using).
Heat olive oil in a large Dutch oven over medium-high heat. Add ground beef and cook for 6-8 minutes until completely browned, breaking into small crumbles. Drain excess grease if needed.
Reduce heat to medium. Add diced onion and cook for 3-4 minutes until softened. Add minced garlic and jalapeño, cooking for 1-2 minutes more while stirring constantly.
Sprinkle taco seasoning and ranch dressing mix over the meat mixture. Stir thoroughly and cook for 1 minute to toast the spices.
Add pinto beans, black beans, corn, fire-roasted diced tomatoes, and diced green chiles with all their liquid. Mix gently to combine.
Pour in chicken broth and stir. Increase heat to high and bring to a rolling boil.
Reduce heat to medium-low to maintain a gentle simmer. Cook uncovered for 20-30 minutes, stirring occasionally, until flavors meld.
Ladle into bowls and top with shredded cheddar, sour cream, diced avocado, fresh cilantro, sliced green onions, and a squeeze of lime juice. Serve with tortilla chips or Fritos on the side.