Grill or bake the chicken at 400°F for 15-20 minutes. Shred with two forks or a hand mixer.
Dice the yellow onion, red pepper, and jalapeños into small, ¼” pieces.
Add in one can of roasted tomatoes and stir again. Let everything simmer for a few minutes. Then, add finely diced cilantro.
Pour in chicken broth and stir the soup. Then, add in the shredded chicken and simmer for 30-40 minutes.
Top your soup with Greek yogurt, tortilla chips, avocado, cilantro, and cheese if you'd like!