1. Preheat oven to 400°.
2. Combine milk, chili powder, 1 tablespoon minced jalapeño, and egg in a bowl, stirring with a whisk. Add muffin mix; stir just until combined. Divide batter among 4 (8-ounce) ramekins coated with cooking spray. Place ramekins on a baking sheet. Bake at 400° for 15 minutes or until a wooden pick inserted in the center comes out clean. Cool on a wire rack for 5 minutes; remove muffins from ramekins.
3. Combine remaining minced jalapeño, tomatillos, and next 4 ingredients (through black pepper) in a food processor; process until almost smooth.
4. Heat a Dutch oven over medium-high heat. Add oil to pan; swirl to coat. Add onion; cook 4 minutes, stirring occasionally. Add garlic; sauté 30 seconds. Stir in tomatillo mixture, stock, and hominy; bring to a boil. Add chicken to pan; simmer, covered, 5 minutes. Turn chicken over; simmer, covered, 5 minutes or until chicken is done. Place chicken on a cutting board; cut into bite-sized pieces. Return chicken to pan. Stir in lime juice. Divide soup evenly among 4 bowls; top with radishes. Serve with corn muffins.