Pat chicken thighs dry with paper towels. In a small bowl, combine 1 tbsp olive oil, paprika, garlic powder, onion powder, thyme, 1/4 tsp salt, and 1/8 tsp black pepper. Rub mixture all over the chicken thighs.

Preheat air fryer to 375°F (190°C). Place chicken thighs in a single layer in the air fryer basket, skin side up. Cook for 20-25 minutes, flipping once halfway through, or until the internal temperature reaches 165°F (74°C) and the skin is crispy. Cooking time may vary. Remove chicken and let rest for 5 minutes.

While chicken is cooking or resting, heat 1 tbsp olive oil in a large skillet over medium heat. Add minced garlic and sauté for 30 seconds until fragrant. Add trimmed green beans, 1/4 tsp salt, and a pinch of black pepper. Cook, stirring occasionally, for 8-10 minutes, or until tender-crisp.

Place peeled and quartered potatoes in a large pot and cover with cold salted water. Bring to a boil and cook for 15-20 minutes, or until fork-tender. Drain potatoes well. Return them to the hot pot. Add milk, butter, 1/4 tsp salt, and a pinch of black pepper. Mash with a potato masher until smooth and creamy.

Serve the rested air fryer roast chicken with garlicky sautéed green beans and creamy mashed potatoes for a complete and delicious meal.