Dry-roast the ragi rava in a pan on low heat 3–4 min until aromatic. Set aside.
Heat the ghee, temper mustard seeds and cumin.
Add hing, curry leaves, ginger. Stir 15 seconds.
Add carrot, cover, cook on low 3 min, then add spinach and wilt 1–2 min until fully soft.
Add water and salt, bring to a boil.
Add the roasted ragi rava in a slow stream, stirring constantly to avoid lumps. Cover and cook on low 4–5 min until thick and soft.
Rest 2 min, add lemon juice, serve warm — eat fresh, as ragi thickens quickly on cooling.
वैरिएशन: If ragi rava is unavailable, mix whole ragi flour with a little water into a thick batter and stir it into the tempering instead, like a porridge.