Step 1: Understanding the Concept:
The question asks for the cooking method used to prepare Idli, a popular South Indian breakfast dish.
Step 2: Detailed Explanation:
Idli is made from a fermented batter of rice and lentils. The process involves:
1. Pouring the batter into molds in an Idli stand.
2. Placing the stand in a special pot with a small amount of water at the bottom.
3. Heating the pot so the water turns to steam, which then cooks the batter.
This method of cooking with moist heat from steam is called steaming.
(B) Frying uses hot oil, (C) Boiling involves submerging in water, and (D) Roasting uses dry heat. None of these are used for making idli.
Step 3: Final Answer:
The method used to make idli is steaming.