Rinse peppers under cold water and pat dry. Slice off tops and bottoms, stand upright, and cut down along the inside to remove seeds and white ribs. Slice lengthwise into ½-inch strips; halve crosswise for shorter pieces. Keep sizes uniform so everything cooks evenly. If adding onion, slice it now. Measure out olive oil, salt, and pepper. Have everything ready before the pan goes on — sautéing moves fast.

Heat a large Skillet over medium heat. Add 1 tbsp olive oil per 2 peppers; warm 30–60 seconds until shimmering. Add pepper strips in a single layer — work in batches if crowded. Season with salt and pepper, stir to coat. Cook over medium heat, stirring every 2–3 minutes, for 6–10 minutes. At 6 minutes: slightly softened with snap. At 10 minutes: tender throughout with light color. For very soft peppers, cook 30–40 minutes over medium-low, stirring occasionally. Add garlic halfway through cooking. If browning too fast, add a splash of white wine or water and briefly cover to steam.

Drizzle the 1 tbsp olive oil over the 4 pieces bone-in, skin-on chicken thighs patted very dry with paper towels and rub it in evenly. Sprinkle the spice mixture all over the chicken, including under the skin where possible, pressing gently so it adheres.

Preheat your Air Fryer to 400°F for 3 minutes. Place the 4 pieces bone-in, skin-on chicken thighs patted very dry with paper towels skin-side down in a single layer in the Air Fryer basket, making sure they don't overlap. Air fry for 12 minutes.

Transfer the 4 pieces bone-in, skin-on chicken thighs patted very dry with paper towels to a plate and let it rest for 3–5 minutes before serving. Serve immediately.