Sprinkle the chicken thighs with salt and pepper and dredge in flour. Melt 2 tablespoons of the butter with the EVOO in a Dutch oven over medium-high heat. Brown the chicken until crisp, and then remove from the pan. Add the ginger, garlic, onions and chiles and sprinkle with some salt. Stir in the ras el hanout, cardamom, cinnamon, cloves and nutmeg, and cook until the vegetables are tender, 10 to 12 minutes.
Pour in 2 cups of the stock along with the squash and tomatoes and simmer 15 minutes. Return the chicken to the pot and simmer to cook through, 10 minutes longer, and then wilt in the spinach. Cool and store for a make-ahead meal, preparing the rice as the chicken reheats over medium heat.
Cook the lentils in boiling salted water until tender, 7 to 10 minutes for red lentils, 15 minutes for brown. Drain and reserve. Meanwhile, bring the remaining 1 cup stock, 3/4 cup water and the remaining 1 tablespoon butter to a boil in another small saucepot. Add the rice and bring to a boil, reduce to a simmer and cook until tender, 16 to 18 minutes. Fluff with a fork, and then combine with the lentils, pomegranate, scallions, cilantro and mint and serve with the chicken.
If you don't have ras el hanout, you can make your own spice blend with 1 1/2 teaspoons each chili powder (ancho or mild to moderate blend, such as Gephardt's chili powder), cumin, coriander and turmeric.