Tomato Braised Chicken Tacos

Name: Tomato-Braised Chicken Tacos
Ingredients: 4 Roma tomatoes; 1 1/2 tsp. kosher salt; 3 jalapeños; 1/4 white onion; 2 clove garlic; 2 tsp. vegetable oil; 2 lb. boneless, skinless chicken pieces; 2 tbsp. minced cilantro; 12 corn tortillas; Avocado salsa (recipe follows); 2 Hass avocados; 3 tbsp. diced red onion; 1 Roma tomato; Juice of 1 lime; 1/2 tsp. kosher salt