In a medium bowl, combine the flours, olive oil, and salt. Add the warm water, a little at a time, while continuing to mix the flour with your hands. Make sure the liquid is well absorbed before adding more. Mix and knead until a soft and elastic dough forms. You do not need to knead this dough excessively as you would for traditional rotis. Cover and let the dough rest for 30-40 minutes.
Heat a tava, griddle or non-stick (preferably cast iron) skillet to medium-high heat, depending on your stove. You may need to lower the heat after you start making the rotis.
Divide the dough into 4 pieces and roll between your hands to form each into a somewhat flat ball. Then place the dough between two pieces of parchment paper and roll out with a rolling pin. In between rolling, remove the top parchment and flatten with your hands. Be careful not to apply too much pressure to the rotis while rolling them out. You do not want them too thin.
Remove the top paper and gently turn out to your hand and place on the hot skillet. Let it cook for about a minute or until the bottom sets, then flip with a large spatula and smear it with a bit of ghee or butter. Let this cook again for about a minute and then flip again, adding more oil or butter, if desired. Flip a couple more times, while pressing gently with the spatula, until the roti is completely cooked. Cover with a cloth and serve immediately.