Season the chicken thighs evenly with sea salt and black pepper.
Heat the coconut oil in a large skillet over medium-high heat.
Place the chicken in the skillet and sear for 4-5 minutes per side until golden brown and nearly cooked through, then remove from the pan and set aside.
In the same skillet, add the diced onion and sliced red bell pepper, sautéing for 3-4 minutes until the vegetables begin to soften.
Stir in the minced garlic, grated ginger, and red curry paste, cooking for 1 minute until highly aromatic.
Pour in the coconut milk and stir well to combine with the curry paste, bringing the mixture to a gentle simmer.
Return the chicken thighs to the skillet, nestling them into the sauce, and simmer for 5 minutes to allow the flavors to meld.
Fold in the fresh spinach and cook just until wilted, then finish the dish with a squeeze of lime juice and a garnish of fresh cilantro.