Preheat the oven to 400°F (200°C).
Place the halved baby potatoes on a baking sheet. Drizzle with 1 tablespoon olive oil, sprinkle with 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper. Toss to coat evenly.
Roast the potatoes in the preheated oven for 25-30 minutes, turning halfway through, until golden and tender.
While the potatoes roast, pat the chicken breasts dry with paper towels.
Season both sides of the chicken breasts with 1 teaspoon kosher salt, 1/4 teaspoon black pepper, and 1 teaspoon garlic powder.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat.
Add the chicken breasts to the skillet and cook for 5-6 minutes without moving, until golden brown.
Flip the chicken breasts and cook for another 5-6 minutes, or until the internal temperature reaches 165°F (74°C). Remove from skillet and let rest.
In the same skillet, reduce heat to medium and add 1 tablespoon butter.
Add the minced garlic and cook for 30 seconds until fragrant.
Add the trimmed green beans and 1 teaspoon fresh thyme leaves. Sauté for 5-7 minutes until the green beans are tender but still crisp.
Season the green beans with a pinch of salt and pepper to taste.
Serve the pan-seared chicken breasts alongside the roasted baby potatoes and sautéed garlic green beans.