In a food processor or blender, blend together white flour, rice flour, cayenne, onion, coconut, salt, yogurt, and 3/4 cup water until smooth. Transfer mixture to a bowl.

Heat 1 tablespoon oil in a small skillet set over medium heat and cook mustard seeds until they begin to pop. Add seeds and oil, along with black pepper, to batter; stir to combine thoroughly.

Have all cooking paraphernalia ready and at hand. You will need to have near your skillet: 1/4 to 1/2 cup of vegetable oil in a cup or bowl with a small spoon, a larger spoon to spread the batter, the bowl of batter with a 1/3-cup measuring scoop/cup, a metal spatula for turning the pancakes, and a plate on which to place the finished dosas after they are cooked.

Pour 1 teaspoon of oil into the skillet and tilt to distribute evenly. Heat the skillet over medium-low until oil is hot. Pour 1/3 cup of the mixture onto the center of the hot skillet. Use the large spoon to spread the batter in a spiral motion, until the pancake is about 6-7 inches in diameter. Turn pancake after 2 minutes and cook another 2 minutes on the other side.

Remove pancake to plate and repeat with remaining batter, adding only enough additional oil to the skillet as needed to keep surface evenly greased. I found that about 1/2 to 3/4 teaspoon for each pancake was plenty, but your mileage may vary.

Serve right away, or reheat (wrapped in aluminum foil) in a 400 F. oven for 15 minutes.

Serve with relishes, pickles, chutney, or cooked vegetables.

Adapted by Karen Mintzias from Madhur Jaffrey's "World-of-the-East Vegetarian Cooking"