Preheat the oven to 425°F.

In a small bowl, combine the softened butter, lemon zest, herbs, garlic, salt, and pepper. Stir to combine and set aside.

Halve the onions and remove the outer skin. Then slice each onion half into ½-inch slices. Spread evenly on the bottom of a 10- or 12-inch oven-safe skillet. Season with a bit of salt and pepper.

Place lemon slices evenly on top of the onions.

On a large cutting board, carefully cut along one side of the chicken’s backbone. Cut along the other side of the backbone to remove it completely. Flip the chicken over and flatten along the center of the breastbone with the heel of your hand. Pat the chicken dry.

Carefully loosen the skin over the chicken breasts and thighs. Take about half of the butter mixture and spread it under the skin. You can distribute it by massaging the outside of the skin.

Microwave the remaining butter mixture until it’s just melted. Brush half of the melted butter on the underside of the chicken.

Place the chicken breast-side-up on the onions and brush with the remaining butter mixture.

Place the chicken in the preheated oven and roast for 30 minutes. Carefully pour wine into the pan around the chicken, not on the chicken, and roast for an additional 15 minutes. Check the chicken with a meat thermometer at the thickest part of the thigh without touching the bone. The internal temperature should be 165°F.

Remove chicken and let rest for 10 minutes before serving.