Dissolve the yeast and sugar in ¾ cup warm water. After the yeast proofs and rises, add all the flours, garlic paste, lemon juice or yogurt, salt and oil to the yeast mixture.
Knead to a smooth dough. Cover with a moist cloth and keep the dough to leaven for 1 to 2 hours.
When the dough doubles up, then make medium sized balls of the dough. Cover and keep aside for 15-20 mins.
In a plate or tray take the chopped garlic, celery leaves and nigella seeds and mix these well.
Take each ball on a dusted board and roll into a small circle of 2 inches.
Place this disc on the garlic-celery-nigella-seeds mixture. Remove and keep on a dusted board and roll to a round of about 5 to 6 inches diameter.
Heat a tava and place the garlic and celery side of the naan touching the hot tava. Cook this side till browned and done.
Now hold the naan with a tong and place the uncooked side directly on fire. Roast this side on the fire till browned and done.