Pat the chicken thighs dry with paper towels and season both sides with sea salt, black pepper, and garlic powder.
Heat 2 tablespoons avocado oil in a large heavy pot or Dutch oven over high heat until shimmering.
Place the chicken thighs skin-side down and brown for 4 to 6 minutes until skin is crispy and golden, then flip and brown the other side about 4 minutes. Transfer chicken to a plate.
Reduce heat to medium and add the chopped onion to the same pot. Cook, stirring occasionally, until the onion is golden-brown, about 5 to 8 minutes.
Add the minced garlic and uncooked rice; sauté and stir constantly for about 3 minutes so the rice browns lightly.
Stir in the drained artichoke hearts, sliced kalamata olives, drained sun-dried tomatoes, chicken broth, and Italian seasoning. Mix to combine.
Return the browned chicken thighs to the pot, arranging them skin-side up in a single layer over the rice mixture.
Cover, bring to a full boil, then immediately reduce heat to low and simmer, covered, for 20 minutes, or until rice is tender and chicken registers 180°F (82°C) at the thickest point.
Remove from heat and let rest a few minutes. Taste and season with additional sea salt and black pepper as needed, then serve.