Rinse the raw rice, urad dal, poha, and fenugreek seeds separately, then combine them in a large bowl and cover with water until fully submerged. Let them soak for at least 4 hours.

Drain the soaked ingredients and grind them in a blender with fresh water, adding it gradually, until the mixture is smooth and pourable like a thick pancake batter.

Transfer the ground batter to a large container, leaving room for it to expand, and let it ferment in a warm place until it has visibly doubled in volume and turned slightly airy and tangy-smelling.

Stir the salt into the fermented batter, mixing gently to keep the airiness intact, and adjust the consistency with a splash of water so it is thin enough to spread easily.

Place a flat cast-iron or non-stick tawa on medium-high heat and let it heat through until a few drops of water sprinkled on the surface sizzle and evaporate instantly.

Pour a ladleful of batter onto the center of the hot tawa and spread it outward in a thin, continuous spiral using the base of the ladle to form a wide, even circle.

Drizzle a small amount of oil evenly around the edges and over the surface of the spread batter to help it crisp up and release cleanly from the tawa.

Let the dosa cook undisturbed on medium-high heat until the base turns golden brown and crisp and the edges begin to lift away from the tawa on their own.

Slide a flat spatula under the dosa, fold it in half or roll it, and lift it off the tawa onto a serving plate.

Wipe the tawa lightly with a damp cloth to reset the surface temperature, then repeat the pouring, spreading, and cooking process with the remaining batter to make the rest of the dosas.