Soak both the rice, toor dal, red chilies, fenugreek in water for 4-6 hrs or overnight.
Drain the water, wash the rice, toor dal in tap water, grind it in a blender along with water until the batter turns smooth and soft. Add salt and mix well with hand. Leave it for 4 hrs or use it immediately.
Heat a dosa pan or griddle, pour a ladleful of dosa batter and spread it like dosa. Drizzle a tsp of oil over dosa or in sides. Cook both the sides until it turns crisp and golden brown colour.
My Tip: You can avoid red chilies and add green chillies, if you don't want spicy side. You can also make dosa without red chilly. You can add grated carrots and curry leaves to the batter also.