Step 1: Preheat your oven to 400°F (200°C). Pat chicken thighs dry with paper towels.
Step 2: In a bowl, rub the jerk seasoning all over the chicken thighs, ensuring they are fully coated. Let them marinate at room temperature for at least 20 minutes, or refrigerate for up to 2 hours.
Step 3: Heat 1 tablespoon of olive oil in a large oven-safe skillet (cast iron works great) over medium-high heat. Place chicken thighs skin-side down and sear for 6-8 minutes, until the skin is golden brown and crispy.
Step 4: Flip the chicken thighs and brush generously with sweet chili sauce. Transfer the skillet to the preheated oven and bake for 20-25 minutes, or until the internal temperature reaches 165°F (74°C).
Step 5: While the chicken bakes, prepare the mashed potatoes. Place quartered potatoes in a large pot and cover with cold, salted water. Bring to a boil, then reduce heat and simmer for 15-20 minutes, or until fork-tender. Drain well.
Step 6: Return the drained potatoes to the pot. Add milk, butter, salt, and pepper. Mash until smooth and creamy. Adjust seasoning as needed.
Step 7: For the broccolini, heat 1 tablespoon of olive oil in a separate skillet over medium heat. Add minced garlic and cook for 30 seconds until fragrant. Add the trimmed broccolini and a splash of water (about 2 tablespoons). Cover and steam for 3-5 minutes, until crisp-tender and bright green. Season with salt and pepper.
Step 8: Remove chicken from the oven and let it rest for 5 minutes before serving. Serve the sweet chili jerk chicken thighs alongside the creamy mashed potatoes and steamed broccolini.