Preheat the oven to 375°F (190°C).
Season the chicken thighs evenly with salt and black pepper.
Heat the olive oil in a large ovenproof skillet or casserole dish over medium-high heat.
Add the chicken thighs skin-side down and cook for 5-7 minutes until the skin is golden brown and crisp. Flip and cook for an additional 3 minutes. Remove the chicken from the skillet and set aside.
Reduce the heat to medium and add the sliced onion to the skillet. Cook, stirring occasionally, until the onion is soft and translucent, about 5 minutes.
Add the minced garlic, ground cumin, ground coriander, ground cinnamon, ground turmeric, and cayenne pepper to the onions. Stir and cook for 1 minute until fragrant.
Pour in the chicken broth, scraping the bottom of the skillet to loosen any browned bits.
Stir in the chopped dates, honey, and lemon juice. Let the mixture simmer for 3 minutes.
Return the chicken thighs to the skillet, skin-side up, nestling them into the sauce.
Transfer the skillet or casserole dish to the preheated oven and bake uncovered for 30 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).
Remove the casserole from the oven and sprinkle the chopped fresh cilantro and toasted sliced almonds over the top before serving.