Dum cooking means sealed steam: par-cooked rice layered over finishing curry, vessel closed, heat lowered, patience applied. No tandoor required.
Preparation that matters:
Boil rice to seven-tenths: a grain pressed between fingers shows a thin white core. Fully cooked rice collapses into mush during dum; underdone rice stays chalky. Drain hot rice fast and spread it so carryover steam stops cooking.
The curry underneath should be thicker and more concentrated than serving consistency. Sealed steam adds moisture back; start tight.
Layering order:
Curry base, half the rice, fried onions-mint-corresponding herbs, remaining rice, finishing touches (saffron milk if used, ghee dots) on top. Two layers suffice for home vessels; three belongs to competition videos.
Sealing options ranked:
Wet cloth wrapped over the lid rim before closing seals well and signals doneness by drying.
Aluminium foil pressed around the rim works and tears open cleanly.
Flour dough paste (the traditional rota) seals best and breaks ceremoniously at serving.
Heat discipline:
Two minutes high to build steam, then the lowest burner flame (or a tawa under the vessel for further insurance against hot spots), twenty-five to forty minutes depending on quantity. Rest sealed another ten off heat.
Vessel shape truth:
Wide and moderately deep beats tall and narrow. Layers stay defined when steam travels sideways through them, and wide bases scorch less at the critical curry-rice boundary.
First attempt advice: halve the recipe. Dum technique settles after one unsealing; learn on a Tuesday, perform on a Sunday.
Layered biryani vessel with dough seal broken open showing rice layers.