1. Soak the rice and urad dal in water for 4-6 hours. Drain and grind with a little water until smooth. Add salt and let ferment overnight or for 8-12 hours.

2. Heat oil in a pan, add mustard seeds, cumin seeds, and curry leaves. Once they splutter, add onion and green chili. Sauté until onions are translucent.

3. Add carrots and green peas, cooking for 5-7 minutes until tender. Stir in turmeric powder, red chili powder, and salt. Add mashed potatoes and mix well for 2-3 minutes. Garnish with coriander leaves.

4. Heat a non-stick or cast-iron skillet over medium heat and grease lightly. Pour a ladle of batter onto the center and spread into a thin dosa. Drizzle oil around the edges and cook until golden and crisp.

5. Place a portion of the spicy vegetable masala in the center, fold the dosa, and remove from the pan. Serve hot with chutney or sambar.