Heat a heavy-bottomed pot over medium heat and add olive oil, listening for a gentle sizzle.
Add chopped onions and minced garlic to the pot, sautéing until fragrant and translucent, about 3-4 minutes. The aroma will fill the kitchen and the onions will soften.
Stir in the diced chicken, cooking until it turns white around the edges, about 5 minutes. This helps lock in the juices and starts the cooking process.
Pour in the broth and add chili flakes or chopped chilies, bringing everything to a gentle simmer. As it heats, the soup will start to bubble softly with steam rising from the surface.
Reduce the heat to low and let the soup simmer uncovered for about 20 minutes, stirring occasionally. During this time, the flavors meld, and the broth becomes rich and slightly cloudy with a spicy kick.
Taste the soup and add a squeeze of lime juice to brighten the flavors. Adjust the seasoning with more chili if desired for extra heat.
Serve the hot soup into bowls, garnished with chopped cilantro or parsley for a fresh contrast. The final dish is hearty with tender chicken, spicy broth, and vibrant green herbs.
