Preheat the oven to 425°F (220°C). Lightly oil a large baking sheet or line it with parchment for easy cleanup.
Pat the chicken thighs dry with paper towels. This helps them get crispy. If you’re using bone-in thighs with skin, you’ll get more flavor from the skin—just make sure it’s dry before roasting.
In a large bowl, combine olive oil, minced garlic, paprika, thyme or rosemary, salt, pepper, and red pepper flakes if using. Whisk until the mixture feels cohesive.
Add the potatoes to the bowl and toss them in the oil and seasonings until evenly coated. Spread the potatoes out on the baking sheet in a single layer.
Place the chicken thighs on the sheet, skin side up, nestling them among the potatoes. If you have extra olive oil, drizzle a light amount over the chicken skin to encourage crispness.
Bake for 35–45 minutes, or until the chicken reaches 165°F (74°C) at the thickest part and the potatoes are golden and tender. If the skin isn’t as crispy as you’d like, switch the oven to broil for 1–2 minutes, watching closely.
Remove from the oven and let rest for 5 minutes before serving. Taste and adjust salt if needed.