Mix together sugar, warm water and active dry yeast. Leave for 10 minutes until yeast activates and is frothy.
Using Bob's Red Mill flour, add in oil, yogurt, salt and yeast. Knead the dough well.
Cover the dough with plastic wrap or damp cloth. Keep in a warm place (oven) for an hour. The dough will double in size.
In a mixing bowl, combine cheese, chillies, red pepper flakes, coriander leaves and salt. Set aside.
Once dough has doubled in size, cut it into 6 equal pieces using a pastry scraper.
Pour some flour onto a clean surface. Using a rolling pin, roll the dough until into a circle, 3 - 4 inches long.
Sprinkle in chili cheese mixture in the middle and seal the edges. Continue rolling into oval shape until it is 6 - 8 inches long.
Heat a cast iron or heavy nonstick skillet over medium-high heat until very hot.
Place the dough in the hot skillet and cook until it puffs up/ bubbles and the bottom is browned or blistered in spots.
Flip the naan and cook a few more minutes.
Brush the cooked naan with melted butter. Serve warm.