In a mixer jar, add 1 cup coarse rava, 1 cup raw potato pieces, salt to taste, and ¾ cup water. Grind it into a smooth batter.
The batter should be medium-thick with a ribbon-like pouring consistency. Transfer it to a bowl and rest for 10 minutes.
Then add ½ cup chopped onion, ¼ cup chopped capsicum, ¼ cup chopped tomatoes, ½ cup chopped coriander leaves, salt, ½ tsp red chilli flakes, and ½ tsp black pepper powder.
In a tadka pan, heat 2 tbsp oil, add ½ tsp mustard seeds, 2 chopped green chillies, 1 inch ginger paste, and 7–8 curry leaves. Sauté well and add this tempering to the batter. Mix properly.
The batter is ready. Add ¼ tsp baking soda and 1 tsp lemon juice. Mix gently; the batter will turn light and frothy.
Heat 1 tbsp oil in a tadka pan, add 1–2 small ladles of batter, cover, and cook on low flame until it is fully cooked and crispy on one side.
Flip gently and cook until both sides turn crisp and golden.
Enjoy crispy sooji nashta with chutney.