In large bowl, mix masa, shortening, chicken broth and salt. Beat with electric mixer on medium speed to make soft dough. In 10-inch skillet, heat oil over medium-high heat. Add onion and garlic; cook until onion is golden brown. Stir in ancho chile powder, yellow chiles and chile paste. Cook about 1 minute to blend flavors. Cool 1 minute; stir into masa mixture until well blended.