Rinse the chicken hearts under cold water and trim any visible fat, connective tissue, or valves. Pat dry thoroughly with paper towels. If any hearts are very large, halve them lengthwise so pieces are similar in size.

Make marinade

Smash or mince the garlic. In a bowl combine olive oil, soy sauce, lemon juice, smashed garlic, smoked paprika, salt, and black pepper. Whisk until blended.

Marinate

Place the prepared hearts in a resealable bag or shallow dish. Pour the marinade over the hearts, toss to coat evenly, and refrigerate for 30 minutes to 2 hours. Do not marinate longer than 4 hours; acid will begin to change texture.

Skewer & Finishing

Soak skewers (if using wooden)

If using wooden skewers, submerge them in water for at least 20 minutes before grilling to prevent burning.

Thread hearts

Remove hearts from the marinade and let excess drip off. Thread 6–8 hearts snugly but not overly tight onto each skewer, leaving a little space so heat circulates and pieces cook evenly.

Preheat grill or pan

Preheat an outdoor grill to medium-high (about 425°F / 220°C) or heat a cast-iron skillet or grill pan over medium-high heat until shimmering.

Cook

Brush grill grates or pan lightly with oil. Place skewers on the hot grill or in the pan. Cook 2–3 minutes per side, rotating to get even sear on all sides (about 6–9 minutes total). Hearts should be browned outside and slightly pink but firm inside — avoid overcooking, which makes them tough.

Finish with butter & herbs

During the last minute of cooking, melt the unsalted butter in a small pan or brush melted butter onto the skewers and sprinkle with chopped fresh parsley and optional chili flakes to taste.

Rest

Remove skewers from heat and let rest 3–5 minutes so juices redistribute.

Serving (optional)

Serve the skewers with lemon wedges to squeeze over and a side of plain yogurt or chimichurri for dipping. Garnish with additional chopped parsley if desired.