Set a griddle to high heat, or if you are using a frying pan, set the stove a couple notches above medium heat. When the pan is hot, use a spatula to spread about a half teaspoon or so (eyeball it) of butter on the pan. The butter should melt immediately. Transfer very thin roti dough to the pan. Wait about 6 or 7 seconds, then flip the roti over. You may need to add more butter; if there is not enough, the roti will not be soft. Roti will cook in 30 to 50 seconds. You will know it is done when light brown spots appear on the side that is cooking. Flip the roti back to the original side (using more butter) just until the brown spots appear.