Trim fat from beef, and cut into 1-inch cubes. Sprinkle with salt and pepper. Heat a large saucepan over medium-high heat. Add beef, and cook 5 minutes or until browned. Add coffee and next 4 ingredients (coffee through garlic), and bring to a boil. Cover, reduce heat, and simmer 45 minutes.
Add taro, mushrooms, dates, and capers; bring to a boil. Cover, reduce heat, and simmer 20 minutes. Serve over rice; top with chayote.