Pot Roast with Vegetables (Carne de Res con Legumbres)

2 tablespoons lard or vegetable oil
1 (3 pound) beef top round roast, tied
2 large white onions, cut into 3/8-inch thick slices
3 large cloves garlic, minced
3 cups beef stock or broth
4 dried pequ?n chiles or 1 dried seeded de ?rbol chile
1/2 teaspoon dried thyme
1/2 teaspoon dried oregano
2 pounds fresh tomatillos, husked, or 2 (13 ounce) cans tomatillos, drained
2 large fresh poblano chiles, roasted, peeled, seeded, de-veined,
    and cut into 1/2-inch wide strips
2 chayote squash
12 small new red potatoes, unpeeled
1/4 cup minced fresh cilantro

Heat lard or oil in large Dutch oven over medium heat until hot. Add beef; cook, turning occasionally, until brown on all sides, 10 to 15 minutes. Remove to plate. Add onions and garlic to pan; saut? over medium heat until soft, 6 to 8 minutes. Add stock, pequ?n chiles, thyme and oregano; heat over medium-high heat to boiling. Add tomatillos to pan. If using fresh tomatillos, cook over medium heat until fork-tender, about 10 minutes. Add beef to pan, pushing it down so it is surrounded by liquid. Place 3/4 of poblano chile strips on top of beef. Heat over medium-low heat to simmering; simmer, partially covered, 2 1/2 hours.

Pare and seed chayote; cut into 1 x 1 1/2-inch pieces. Add chayote and potatoes to beef; simmer, covered, over medium-low heat until potatoes and beef are fork-tender, 30 to 40 minutes longer. Remove beef, potatoes and chayote to warm serving platter; keep warm, covered. Process 1/2 the cooking sauce in blender at a time until smooth. Return sauce to pan; cook over medium heat, stirring occasionally, until reduced to 4 cups, 20 to 25 minutes. Stir in cilantro.

Garnish beef with remaining poblano chile strips. To serve, cut beef across grain into thin slices. Pass sauce separately.

Makes 6 to 8 servings.