Soak corn husks in warm water for a minimum of 30 minutes to make pliable. Weigh husks down with a plate to keep husks submerged.
For Salsa
Heat 2 tablespoons oil in a large nonstick skillet over medium-high heat. Add onions and garlic and cook until onions are tender, about 3 to 5 minutes. Add remaining salsa ingredients. Bring to a boil, reduce heat to medium and simmer 10 minutes or until tomatoes are cooked through. Remove from heat and cool 5 minutes. Puree in blender or food processor; set aside.
For Tamales
Combine chicken, cheese, cilantro, frozen vegetables, roasted red peppers and 2 cups salsa in large bowl. Stir in oil and cornmeal mix until well combined.
Remove 2 corn husks from water and tear each into 1/4-inch strips for tying up the tamales; set aside.
To assemble tamales: unfold corn husk and place on work surface. Starting at top edge of the wide end of the husk, spoon 1/2 cup filling down center of husk. Mold into a 4-by-2-inch rectangle, leaving several inches of room at the bottom for folding. Fold in each side of husk. Fold end of the husk and tie with one of the pre-torn strips of husk. Repeat with remaining husks and ties.
Add 1-inch of water to a deep pot with a tight fitting lid. Place steamer basket in the pot. Arrange tamales upright with closed-ends facing down in the basket. Bring the water to a boil over medium-high heat. Cover, reduce heat to low and steam 45 minutes to 1 hour. Add more water as needed.
Remove tamales from steamer and let stand 5 minutes. Transfer tamales to a platter; untie and open husks. Garnish with additional chopped fresh cilantro. Serve with remaining salsa.
Recipe Note #1 – If self-rising corn meal mix is not available at your local grocer, you can use this substitution recipe: 2 cups instant masa harina combined with 1 teaspoon baking powder and 2 teaspoons salt.
Recipe Note #2 – Set a steamer basket (the type that expands) in a deep pot OR use a deep style steamer.