Combine flour, yeast, salt, and sugar together in a large bowl. Add yogurt and milk, then knead until dough comes together in a smooth ball.
Knead for 5 more minutes. Cover bowl with plastic wrap and let rise until doubled, about 2 hours.
Turn dough onto a floured surface and divide into 12 equal pieces. Roll each into a ball and cover with a floured towel. Let rise until doubled, about 2 hours.
Preheat oven to 500°.
Roll each ball into a disk about 1/4" thick and 7" in diameter.
Cover the exterior of oven-safe ramekins with foil and set upside-down on a baking sheet. Spray ramekins with nonstick oil, then drape dough over each ramekin. The dough should almost - but not quite - touch the baking sheet. Prick the flat top of the dough with a fork several times.
Bake at 500° for 8 minutes. Lift the naan off of the ramekins and set the ramekins aside. Set the bread bowls right-side-up on the baking sheet and broil for 1-2 minutes, until insides are golden.
Fill the naan bowls with your favorite curry and serve hot!