Dense and lush with chocolate, dried tart cherries and a crunch of pistachio nuts are the perfect foil to a combination of brown rice and oat flours in these not-too-sweet muffins.
Preheat oven to 375°F. Butter 12 regular muffin cups. Sift brown rice flour, oat flour, brown sugar, baking powder, flax meal, and salt into a medium bowl. Whisk buttermilk and egg in another medium bowl; whisk in the olive oil. Add buttermilk mixture to dry ingredients; stir just until incorporated (do not overmix). Fold in the cherries and pistachio nuts.
Divide batter equally among prepared muffin cups and place in the oven. Bake muffins until tester inserted into center comes out clean, about 15 minutes.
Remove from oven and cool in the pan for 10 minutes before turning out onto a rack to cool completely.