Preheat the oven to 375°F. Lightly grease a muffin dish, or place  cupcake cases in a cupcake dish. Combine the flour, baking powder, baking soda, salt & pepper, grated SB parsley chive cheese  and chopped spinach in a large bowl. In a separate bowl, combine the buttermilk, mustard with the oil and the eggs, and beat lightly. Add the wet ingredients to the dry, and fold in until just combined. Distribute the mixture evenly between the cupcake cases Bake for 30 minutes, or until the muffins are golden brown on top. After allowing to cool for a few minutes, transfer to a wire rack to cool completely. Another great variation can be substituting spinach with sauté kale.