In a small bowl, combine yeast, sugar, and 1/4 cup warm (110 to 115 degrees F) water; let stand until foamy, 5 to 10 minutes.
Into the bowl of your food processor, place 4 1/2 cups flour, salt, and baking powder; fit with the dough blade (or use a stand mixer with the dough hook) and mix to combine.
Add in the yeast mixture, milk, yogurt, egg, 2 tablespoons vegetable oil, and 3/4 cups warm water and knead until smooth and elastic (2 to 3 minutes - food processor; 5 to 8 minutes - mixer; 8 to 10 minutes - by hand); dough should be soft, but not too sticky, so add flour as needed.
Lightly oil a large bowl, add dough, turning to coat, then cover bowl with plastic wrap, then a clean kitchen towel; let dough rise, in a warm place, until doubled, about 1 to 1 1/2 hours.
Punch dough down and divide into 8 equal pieces, which you will roll into a ball and place on a lightly floured baking sheet; cover with a damp kitchen towel, and let rise until doubled, about 40 to 60 minutes more.
If using a tandoor, heat it to 450 degrees F (if using your oven, place a pizza stone on bottom rack and heat to 450; or the grill should be st for direct heating at medium-high heat).
On a lightly floured work surface, roll each dough ball into a disk about 5 inches in diameter; roll and stretch one end to form a teardrop shape.
If using a tandoor, drape a piece of dough over the round cloth gadhi, then press bread onto the hot clay wall; cook until the top puffs, gets blishtered and browned, 1 to 2 minutes; gently pry off clay wall and spread with ghee.
If using the oven, turn on the broiler, lay 1 or 2 pieces of dough on the pizza stone, and cook until the bottoms are browned and the tops blister and puff and are lightly toasted, 2 to 4 minutes; remove from oven and spread with ghee.
If using the grill, oil the grate lightly, then lightly brush the dough with butter, place buttered side on grill and cook until the bottom is browned and the top is puffed 1 to 2 minutes; lightly butter the top of the dough, then flip and grill the other side until lightly browned, 1 to 2 minutes.