Add chicken breasts (I used frozen but you could use defrosted), chicken stock, milk, quinoa, rotel tomatoes, green chiles, taco seasoning, and a healthy pinch of sea salt and pepper to your slow cooker. Cover and cook on low 6 to 8 hours (could also cook on high 3 to 4 hours).
About 30 minutes before you’re ready to eat, remove lid and shred chicken inside slow cooker using two forks (could also remove the chicken, shred it using my mixer hack then place it back in the slow cooker). Next, stir in your frozen corn and 1-2 cups of water (depending on how liquid-y you want your soup), then place the lid back on the slow cooker and cook for an additional 30 minutes on high.
Remove lid, ladle into bowls, then garnish with sliced green onions, shredded cheddar cheese, minced cilantro, and/or tortilla chip crumbs!