In a large pot, heat 1 tbsp of olive oil and sauté the onions and salt for 3 minutes.: The scent of sizzling olive oil and softening onion is the first sign the dish is coming alive, with gentle sweet notes emerging as the onion becomes translucent. You should hear a soft sizzle and see glossy edges, which indicates the sugars are releasing; if the pan smokes, you are using too much heat. Take your time here because a properly softened onion forms the foundation of the soup, contributing a mellow backdrop that balances the acidity later. A common pitfall is crowding the pan, which steams rather than sautés, preventing caramelization.
Add the bell peppers, garlic clove and cumin and sauté for an additional 2 minutes.: Once the bell pepper hits the pan, its bright aroma mingles with the warm perfume of cumin , creating a rounded, savory fragrance. You will notice a quick uptick in smell as the garlic hits the hot oil, so stir frequently to avoid scorching, which would introduce bitterness. Visually, the pepper should soften without collapsing, keeping a slight snap that adds texture later. If the garlic browns too quickly, reduce heat and remove the pan from direct high flame for a moment.
Add the broth and remaining ingredients (except for the lime juice & tortilla chips). Bring to a boil, cover, then reduce to a simmer.: When you pour in the chicken broth and the remaining ingredients including the diced tomatoes , the pot will steam and the aroma will broaden into a comforting, savory cloud. Bringing it briefly to a boil helps the ingredients start to meld, but switching to a gentle simmer keeps the broth clear and stops it from reducing too aggressively. Covering the pot traps aromatics so flavors steep evenly. Avoid a rolling boil which can toughen the chicken and evaporate too much liquid.
After 10-15 minutes (depending on the size of your chicken breasts) remove the chicken from the pot and shred, using a fork or hand mixer. Place the shredded chicken back into the pot with the lime juice and simmer for another 3-4 minutes or until chicken is heated though.: At this stage the chicken breast should release juices when pierced and be tender enough to shred, with a subtle steamed aroma. Pull it out and let it rest briefly before shredding to retain moisture, then either fork shred or pulse gently with a hand mixer for uniform ribbons. The goal is tender strands that soak up the broth, not dry shreds, so avoid overcooking which causes dryness. A frequent error is leaving the shredded meat in the hot pot to cook more, which can lead to stringy texture.
Remove bay leaf, pour soup into bowls, and top with crushed tortilla chips for everyone to stir in on their own. Serve with desired toppings on the side.: Returning the shredded chicken to the gently simmering broth allows it to absorb the seasoned liquid, and the fresh squeeze of lime will brighten the entire pot with a citrusy lift. You should see tiny bubbles around the edge and smell a lively balance of savory and acid. Keep the heat low so the lime maintains its brightness, and do not let it bubble vigorously which will dull the citrus notes. If the soup tastes flat at this point, a small pinch more salt can sharpen the flavors.
Remove bay leaf, pour soup into bowls, and top with crushed tortilla chips for everyone to stir in on their own: The final act is all about texture and presentation, remove the bay leaf and ladle the steaming soup into bowls so each diner can add their preferred amount of crushed tortilla chips . The chips should be added at the table so they remain crunchy until mixed in; when combined they soften slightly and add a pleasant toasted corn note. Serve the toppings of choice on the side so each bowl becomes a personalized experience. A common mistake is adding chips too early which leads to a soggy texture rather than the intended satisfying crunch.