Heat oil in a frying pan and sauté cumin seeds until fragrant. (If using powdered cumin, add later with other spices.)
1 tsp cumin seed, 2 tbsp oil
Add onions and sauté until soft.
200 g onion
Add carrots, potatoes, tofu, garlic, and ginger; sauté lightly.
140 g carrot, 300 g potato, 140 g thick fried tofu, 1 tbsp grated garlic, 1 tbsp grated ginger
Stir in coriander, turmeric, and optional cayenne for 30 seconds; avoid burning.
1 tbsp coriander powder, 1 tsp turmeric powder, cayenne pepper
Pour in water, onion koji, sugar, soy sauce, and salt. Bring to boil, reduce heat, and simmer 10 minutes until vegetables are tender.
1 tbsp onion koji, 1 tbsp sugar, 2 tsp soy sauce, 1 tsp natural salt, 700 ml water
Turn off heat, let flavors infuse 30 minutes.
Stir in rice flour dissolved in water; cook on low for 3–5 minutes, stirring continuously.
2 tbsp rice flour, 4 tbsp water
Serve over rice. Taste and adjust seasonings as desired.