Heat a large pot or Dutch oven over medium-high heat. Add the ground beef and diced onions, breaking up the meat as it cooks until it's no longer pink and the onions are softened, about 5-7 minutes. Drain excess fat if needed, leaving about 1 tablespoon in the pot for flavor. Add the garlic powder and ground cumin, stirring constantly for about 30 seconds to toast the spices and release their aromatic oils—this is crucial for building authentic taco flavor that won't come through if added later.

Add the drained and rinsed black beans, drained corn, diced tomatoes, diced tomatoes with chiles, canned green chiles, chili beans (with their liquid for body and richness), and chicken broth to the pot with the browned beef mixture. Sprinkle the taco seasoning packet and ranch dressing mix directly over everything and stir thoroughly to combine all ingredients and dissolve the seasoning packets evenly throughout the liquid. I find that adding the seasoning packets directly and stirring well ensures the flavors are evenly distributed rather than clumping in one area.

Reduce heat to low and cover the pot with a lid, leaving it slightly ajar to allow some steam to escape. Simmer for 4-6 hours, stirring occasionally (every hour or so) to prevent sticking and ensure even flavor distribution. The long, gentle simmer allows the ranch seasoning, taco spices, and all the bean and vegetable flavors to meld together into a cohesive, deeply flavored soup. I prefer the longer end of this range—around 5-6 hours—because it gives the flavors more time to develop and creates a richer, more complex taste.

Taste the soup and adjust seasoning as needed—add a pinch of salt if it needs more depth, or extra cumin if you want more taco flavor. Ladle the soup into bowls and top generously with shredded cheddar cheese, a dollop of sour cream, and a handful of tortilla chips for contrast in texture and added richness. The chips will soften slightly as they sit in the warm soup, creating a satisfying bite.