In medium bowl, combine lamb, 1 teaspoon salt and 1/2 teaspoon pepper; toss to evenly coat. In Dutch oven, over medium-high heat, heat oil; add lamb, yams, onion, ancho chile powder, garlic, cumin and oregano. Cook, stirring frequently, for 5 minutes. Stir in tomatoes with their liquid, broth and remaining 1/2 teaspoon salt. Bring to a boil; reduce heat to medium and simmer, uncovered, 35 minutes, stirring occasionally. Stir in black beans. Reduce heat to medium-low and simmer 10 minutes stirring often to prevent burning.