Preheat your grill to medium-high heat, about 375°F to 400°F. Make sure the grates are clean and lightly oiled to prevent sticking.

While the grill is heating up, pat the chicken breasts dry with paper towels to ensure a nice sear when grilling.

Drizzle the olive oil over both sides of the chicken breasts, making sure they are evenly coated.

In a small bowl, combine the honey, Dijon mustard, apple cider vinegar, garlic powder, onion powder, salt, and black pepper. Stir the mixture well until everything is fully blended into a smooth sauce.

Brush both sides of the chicken breasts with the honey mustard mixture, reserving a small amount of the sauce for later basting and serving.

Place the chicken breasts on the preheated grill and cook for about 6 to 7 minutes on each side, or until the internal temperature reaches 165°F. Be sure to flip the chicken carefully to avoid losing the marinade.

While the chicken is grilling, trim the ends of the green beans and rinse them under cold water to remove any dirt or debris.

Bring a large pot of salted water to a boil on the stove over high heat.

Once the water is boiling, add the green beans and cook them for about 4 to 5 minutes, just until they are tender but still crisp.

After the green beans are done, drain them in a colander and set them aside.

Heat a large skillet over medium heat on the stove and melt the butter in it. Once the butter is melted, add the green beans to the skillet and toss them around for 2 to 3 minutes, allowing them to absorb the butter and develop a bit of flavor.

Remove the chicken breasts from the grill and let them rest for a couple of minutes before serving. This helps the juices redistribute and keeps the chicken moist.

Serve the grilled chicken breasts alongside the buttery green beans, and drizzle any remaining honey mustard sauce over the chicken for extra flavor.