Blend all the stew base ingredients until smooth. Transfer to a pot and cover partially with a lid. Bring to the boil then reduce heat to medium-low and cook, stirring and scraping the bottom occasionally, until reduced by half – about 30 minutes. Remove from heat and set aside.

In a large pot, heat two tbsps oil over medium heat. Add half the sliced onion, bay leaves, 2 tsps curry powder, dried thyme, a large pinch of salt, and a large pinch of pepper. Cook, stirring, until fragrant and the onion softens slightly – about three minutes.

Stir in tomato paste and 2 tsps butter. Cook, stirring continuously, until the tomato paste darkens – about three minutes. Add in the stew base, cover partially with a lid and gently simmer until reduced by half – about 15 minutes.

Stir in stock, add the remaining 2 tsps curry powder, ginger and garlic powder, and bring to a boil. Taste and adjust seasoning.

Stir in rice until evenly coated in sauce. Cover the pot with a double parchment (or foil) paper, crimped down around the edges to seal, then top with lid. Reduce heat to lowest possible and cook for 20 minutes, then uncover and gently stir rice to redistribute. Cover again and continue until rice is just cooked through but still retains a firm bite and the liquid is mostly absorbed, about 15 minutes.

Stir in sliced tomato with remaining sliced onion and 1 tsp butter. Remove from heat, cover, and let stand for 10 minutes. Serve.