Preheat oven to 400 degrees. In a saucepan, bring broth, 2 1/2 Tbsp. of butter, Mayan Sea Salt, and Coarse Black Malabar Pepper to a boil. Add spinach to boiling broth (if using fresh, add a handful at a time and let wilt before adding more). In a 3-quart baking dish, mix orzo, feta, Dill Weed, and lemon juice. Pour broth mixture over orzo and stir to incorporate.
Mix breadcrumbs, lemon zest, 1/2 cup Parmesan, and remaining spices. Coat chicken thighs with remaining 2 1/2 Tbsp. melted butter and roll chicken thighs in the breadcrumb mixture. Lay pieces evenly on top of the orzo mixture in the the baking dish.
Bake until orzo is tender and cooking liquid is creamy, 35 to 40 min. Sprinkle remaining 1/2 cup Parmesan on top and bake 10 min. longer or until the top is golden brown. Remove from oven and let stand for 5 to 10 min. before serving.