Dating back to pre-Columbian times, Anticuchos are a staple of Bolivian and Peruvian gastronomy. The most authentic version uses beef heart, which is lean, but the correct marinade softens it and gives it a deep, smoky, and slightly sour flavor.
The acid from the vinegar helps tenderize the meat, while ají panca paste (a mild, smoky red chili) adds color and the typical flavor. The key to success is high heat and short grilling time to keep the heart tender.
In a bowl, mix the ají paste, vinegar, garlic, cumin, oregano, salt, and pepper to create a thick marinade.
Add the beef heart pieces to the marinade, ensuring the meat is evenly coated.
Cover the bowl and refrigerate for at least 4 hours, ideally 8 to 12 hours (overnight).
Boil the potatoes in salted water until tender (about 20–25 minutes). Once cooked, let them cool; they can be peeled and sliced thickly or served whole.
Remove the meat from the marinade and thread onto the prepared skewers (3–4 pieces per skewer). Reserve the marinade for basting.
Heat the grill (preferably charcoal, but a gas grill or grill pan also works) to high heat.
Place the Anticuchos on the grill. Grill for about 2–3 minutes per side until they are dark and crispy on the outside and medium-rare inside. If grilled for too long, the heart will become tough.
While grilling, baste the skewers with the reserved marinade mixed with a little oil. This creates a flavorful crust and keeps the meat juicy.
Remove the Anticuchos from the grill and serve immediately. They are traditionally served with 1–2 slices of boiled potatoes on the plate and sprinkled with chopped parsley.
Serve with fresh and spicy Llajua sauce (Bolivian salsa) or peanut sauce to balance the smoky flavor of the meat.