Heat the olive oil in a wide skillet over medium heat. Add the halved potatoes and sear, turning occasionally, until golden, about 8 to 10 minutes.

Add the sliced onion and cook until softened and beginning to brown, 6 to 8 minutes.

Stir in the cherry tomatoes, chili, garlic, lemongrass if using, white wine, paprika, salt, sugar, and curry powder. Cover the skillet and simmer gently over low heat for 20 minutes.

Uncover, add the spinach, and nestle the salmon fillets into the mixture; cook, turning once, until the flesh is opaque and lightly browned, about 2 to 3 minutes per side (depending on thickness).

Pour in the cream and simmer until the sauce thickens slightly, about 4 to 6 minutes. Taste and adjust seasoning.

Finish with chopped parsley and a squeeze of lemon juice. Serve immediately.