Melt 2 tablespoons butter in a large saute pan over medium-high heat. Saute spinach with salt just until leaves are wilted. Set aside. Melt remaining butter in a medium saucepan over medium-high heat. Saute onion until lightly browned. Lower heat, add ground spices and stir. Add cooked rice, tomatoes and spinach. Cook just enough to heat rice through, stirring well to combine. Serve warm with grilled fish or veal chops. Serves 2-4.