Skewers with Tare Sauce (Japanese Barbecue)

Prepare the Tare sauce by combining sugar, soy sauce, sake, and mirin in a saucepan.

Bring the Tare mixture to a boil over heat, stirring constantly.

Once boiling, reduce the heat to low and let the sauce simmer and reduce.

Prepare the skewers using pieces of chicken, beef, and chicken hearts, assembling them onto the skewers.

Grill the skewers over hot coals.

While grilling, brush the Tare sauce onto the skewers, turning them at least three times on each side to create caramelized layers.