Rinse the jasmine rice under cold water until the water runs clear to remove excess starch. Combine rinsed rice, 2.25 cups water, 0.5 tsp salt and 1 tbs butter (or oil) in a medium saucepan. Bring to a gentle boil over medium-high heat, then reduce heat to low, cover and simmer for 15 minutes. Remove from heat and let sit covered for 10 minutes, then fluff with a fork and keep warm.

For the chicken and curry sauce

Prepare chicken

Pat the chicken thighs dry with paper towels. Season both sides with 1.5 tsp kosher salt and 0.75 tsp black pepper. Lightly dredge each piece in 3 tbs all-purpose flour, shaking off excess. If using boneless thighs, reduce cooking time slightly (see browning step).

Brown the chicken

Heat 2 tbs vegetable oil and 1 tbs butter in a large heavy skillet or Dutch oven over medium-high heat until shimmering. Add the chicken thighs skin-side down (or presentation side first for boneless) and brown without moving for 4–5 minutes until deep golden. Flip and brown the other side 3–4 minutes. Remove chicken to a plate and set aside. Work in batches if necessary to avoid overcrowding.

Sauté aromatics and vegetables

Reduce heat to medium. Add the chopped onion to the same pot and sauté for 4–5 minutes, scraping up browned bits. Add the diced carrot and celery and cook 3–4 minutes until beginning to soften. Add minced garlic and cook 30 seconds until fragrant.

Build the curry flavor

Stir in 2 tbs mild curry powder and 1 tbs tomato paste; cook 1–2 minutes to bloom the spices. Sprinkle the additional 2 tbs flour over the vegetables and stir to incorporate; cook 1 minute to take the raw edge off the flour.

Deglaze and simmer

Slowly pour in 3 cups chicken stock while whisking to dissolve flour lumps and scrape any fond from the bottom of the pot. Add 1 tsp Worcestershire sauce and 1 tsp brown sugar. Bring to a gentle simmer.

Braise the chicken

Return the browned chicken thighs to the pot, skin-side up if applicable, nestling them into the sauce. Reduce heat to low, cover partially, and simmer gently for 25–30 minutes (20–25 minutes for boneless) until the chicken is cooked through and tender and internal temperature reaches 165°F (74°C). Stir occasionally but avoid dislodging skin.

Finish the sauce

Remove the chicken to a warm plate. If the sauce is too thin, increase heat to medium and simmer uncovered for 4–6 minutes to reduce. Stir in 1/2 cup cream and 1 cup frozen peas; simmer 2–3 minutes until peas are heated through. Taste and adjust seasoning with salt and pepper. Stir in 2 tbs chopped parsley and 1/2 tbs lemon juice to brighten the sauce.

Return chicken and serve

Return chicken to the sauce to rewarm for 1–2 minutes. Spoon jasmine rice onto plates or a serving platter, place chicken on top or beside the rice and ladle golden curry sauce and peas over. Garnish with chopped spring onion or extra parsley and serve with lemon wedges on the side.