Whisk ¼ cup olive oil, 3 tablespoons lemon juice, 1 tablespoon Italian seasoning, 2 minced garlic cloves, 1 ½ teaspoons kosher salt, ½ teaspoon black pepper, and ½ teaspoon red pepper flakes if using together in a medium bowl.

Add 2 pounds chicken breast chunks, and toss to coat. Cover and refrigerate for at least 30 minutes or up to 1 hour.

Meanwhile, stir 1 cup dried Italian-style breadcrumbs, 1 ounce finely grated Parmesan cheese, 2 tablespoons finely chopped fresh parsley leaves, and 1 teaspoon garlic powder together in a shallow dish or large bowl.

Heat the oven to 400 degrees F. Fit a wire rack into a rimmed baking sheet.

Add one beaten large egg to the chicken and toss until evenly coated.

Transfer all the chicken to the breadcrumb mixture and toss until the chicken is well coated.

Thread the chicken pieces onto the skewers (about 6 pieces per skewer, they can be just touching). Arrange the skewers on the rack, spacing them evenly apart.

Bake the spiedini until cooked through, golden brown, and an instant-read thermometer registers at least 165 degrees F, 30 to 40 minutes.

Meanwhile, make the garlic butter sauce by microwaving 4 tablespoons unsalted butter cut into pieces, 1 minced garlic clove, and 1 pinch kosher salt in a small microwave-safe bowl until the butter is melted and the garlic is fragrant, about 1 minute.

Stir in 1 teaspoon finely chopped parsley leaves. Brush or drizzle the spiedini with the garlic butter sauce before serving.