Spatchcock a whole chicken by removing the backbone (spine) with a knife or kitchen shears. Lay the spatchcocked chicken on a baking sheet and pat dry. Season the cavity generously with salt and pepper. Then flip the bird and season the breast, legs, and thighs generously with salt and pepper.
In a bowl, mix together yogurt, sage, thyme, garlic, smoked paprika, honey, and lemon juice. Rub the chicken thoroughly with the mixture. Place the chicken on a clean baking rack, and then set the rack on a clean baking sheet. Top chicken with lemon slices and refrigerate for at least 6 hours or overnight.
Tip: If your fridge can’t fit a full baking sheet, marinate chicken in a glass baking dish, or storage container, ideally uncovered.
When ready to cook, prepare a gas or charcoal grill to medium heat, between 350-425°F. Brush grill grates with oil. Drizzle oil all over the chicken, and place the bird on the grill cavity-side down. Close the grill top and cook for about 10 minutes.
Flip chicken and close grill top to cook for another 20-30 minutes until skin is crisp and golden brown, and chicken juices run clear. Internal temperature should reach 165°F.