1. In a large bowl, dissolve yeast in warm water. Let stand about 10 minutes, until frothy. Stir in sugar, milk, egg, salt, and enough flour to make a soft dough. Knead for 6 to 8 minutes on a lightly floured surface, or until smooth. Place dough in a well oiled bowl, cover with a damp cloth, and set aside to rise.
2. Let it rise 1 hour, until the dough has doubled in volume.
3. Punch down dough, and knead in garlic. Pinch off small handfuls of dough about the size of a golf ball.
4. Roll into balls, and place on a tray. Cover with a towel, and allow to rise until doubled in size, about 30 minutes.
5. During the second rising, preheat grill to high heat.
6. At grill side, roll one ball of dough out into a thin circle. Lightly oil grill. Place dough on grill, and cook for 2 to 3 minutes, or until puffy and lightly browned. Brush uncooked side with butter, and turn over. Brush cooked side with butter, and cook until browned, another 2 to 4 minutes. Remove from grill, and continue the process until all the naan has been prepared.