Heat the olive oil in a skillet over medium heat. Add the minced garlic and sauté for about 30 seconds until fragrant, being careful not to burn it.
In the slow cooker, place the chicken breasts and pour the chicken broth over them.
Add the sautéed garlic, ground cumin, smoked paprika, salt, and pepper to the slow cooker. Give it a gentle stir.
Add the rinsed quinoa, diced red bell pepper, black beans, and corn on top of the chicken in the slow cooker. Do not mix; just let the ingredients layer.
Cover the slow cooker and cook on low for 6 hours or high for 3 hours, or until the chicken is tender and fully cooked.
Once finished cooking, shred the chicken with two forks in the slow cooker, mixing it well with the other ingredients. Adjust seasoning if needed.
Serve the protein-packed dish in bowls and garnish with sliced green onions and fresh cilantro if desired.