What is an optimal way to make tandoori roti and naan in big green egg?
I make naan on my BGE all the time. You can't replicate a tandoor, however, the results are very good. I find it best to cook the naan directly on the grill, and over the coals.  I find lower heat is best.  I either bake them at the end of a grill session, when the heat is dying, or I completely close the bottom vent (leaving the lid open...not just the lid vent). Depending on the heat level, it only takes a minute or two on each side.  I place the rolled out naan on the grill, lightly brush with melted butter, wait for bubbling/puffing, flip, brush with butter, wait for puffing (or peak underneath and look for doneness), then remove to a towel for holding...repeat.