Whisk together the yeast, water, and sugar in a large mixing bowl until frothy. Add the olive oil and Greek yogurt. Stir to combine. Add the flour, salt, and baking soda to the bowl. Stir with a wooden spoon until dry ingredients are combined into wet ingredients.

Using clean hands, knead the mixture until a tacky dough forms, 1-2 minutes. Cover the bowl with plastic wrap or a clean kitchen towel and set aside to rise until doubled in volume, about 2 hours.

Place a pizza stone on middle rack of oven. Preheat the oven to 450°F.

Turn dough onto a well-floured surface and divide into 6 equal pieces. Use a rolling pin to roll each piece to a scant 1/4-inch thick.

Open oven and swiftly place naan dough pieces on the pizza stone. Bake until slightly risen, about 5 minutes.

Open oven once more, and flip the naan. Continue baking until golden brown on both sides, about 3 minutes.

Check to see that naan is done. Remove from oven or add time as needed.

Brush naan on both sides with the melted butter, if desired, and serve.