Preheat your oven to 425°F (220°C).
Pat dry the chicken thighs with paper towels. Season them with salt, black pepper, paprika, and bayou city seasonings. Set aside.
In a large bowl, combine the quartered red potatoes, sliced carrots, halved Brussels sprouts, sliced red onion, and minced garlic.
Drizzle olive oil over the veggies, add fresh rosemary, and season with salt and black pepper. Toss until everything is well coated.
Line a large baking sheet with parchment paper or lightly grease it.
Arrange the seasoned chicken thighs on top of the prepared veggies, ensuring they are spread out evenly.
Place the sheet pan in the preheated oven and bake for 40 minutes or until the chicken reaches an internal temperature of 165°F (74°C) and the veggies are golden brown and tender. If the chicken is done before the veggies, you can remove the chicken and let the veggies continue cooking.
Carefully remove the sheet pan from the oven.
Plate the chicken and veggies, ensuring a mix of colors on each plate.
Garnish with additional fresh rosemary if desired.