Season chicken with oregano, 1 teaspoon sea salt and black pepper. Set aside.
Add dried guajillo peppers into a saucepan and cover with water (at least 1 cup). Bring to a boil, reduce to a simmer and cook for about 10 minutes, or until the peppers have softened.
Add peppers and ¾ cup water from saucepan into a high-powered blender. Add onion, garlic, cumin, cloves and ½ teaspoon salt; blend until smooth.
Add oil to a large saucepan on medium heat. Add chile pepper purée into the pan and reduce heat to medium-low. Cook, uncovered, stirring frequently, until thickened, about 10 minutes. Add broth, seasoned chicken cubes, sweet potato and broccoli stems into the saucepan. Cover and simmer until chicken is tender and cooked through and sweet potatoes are fully cooked, this should take about 10-15 minutes. Stir in baby spinach until wilted and season with additional salt, if needed.
Portion soup into bowls and top with avocado, sliced radishes and cilantro. Serve with a lime wedge for squeezing over the top.