Combine all ingredients to prepare marinade. Set aside.
Remove fat and clean beef heart and cut in ľ to 1-inch pieces (2 ˝ - 3 cm.). Place them in a medium size bowl and pour marinade over beef heart pieces. Leave marinating at least 12 hours.
Thread 3 pieces onto bamboo skewers.
Heat barbecue grill and place anticuchos, brushing them with a mixture of blended fresh yellow ají and oil. Cook on one side, turn and repeat procedure. Serve hot.
Usually, 2 anticucho skewers are served per person together with a boiled potato, a piece of corn and blended fresh yellow ají, for a spicier flavor.
If beef heart is not available, anticuchos can be prepared with tenderloin pieces. Proceed in the same way.