12 ounces lean, boneless lamb, cut into 1-inch cubes 
2 cups beef broth 
1/4 teaspoon salt 
1/8 teaspoon pepper 
1 bay leaf 
3 medium potatoes, peeled and cut into 1-inch chunks 
2 medium onions, cut into wedges 
1 1/2 cups sliced carrots 
1/2 teaspoon dried thyme, crushed 
1/2 teaspoon dried basil, crushed 
1/2 cup cold beer or water 
2 tablespoons all-purpose flour 
1/3 cup dairy sour cream 
2 teaspoons snipped fresh mint