Heat olive oil in a large heavy-bottomed pot over medium heat. Add chopped onion and cook until fragrant and translucent, about 3 minutes.
Add minced garlic and cook for another minute until it becomes fragrant, stirring constantly to prevent burning.
Stir in diced chicken breasts and cook until they are lightly browned and cooked through, about 5 minutes, stirring occasionally.
Pour in chicken broth and bring the mixture to a gentle simmer. Add chopped tomatoes, corn kernels, and sliced jalapeños to the pot.
Reduce the heat to low and let the soup simmer gently for 20 minutes, allowing flavors to meld and chicken to become tender.
Taste the soup and season with salt as needed. Squeeze fresh lime juice into the pot for brightness, then stir in chopped cilantro.
Ladle the hot soup into bowls, ensuring each serving has plenty of chicken, corn, and spicy jalapeños. Serve immediately, garnished with extra cilantro and lime if desired.