Pour in the coconut milk and vegetable broth, stirring to combine. Bring the mixture to a gentle simmer.
Add the fish sauce and brown sugar, continuing to stir until the sugar has dissolved.
Bring the curry to a simmer again, then introduce the sliced red bell pepper and green beans. Cook for about 5 minutes until the vegetables start to soften.
Gently add the salmon fillets into the pan. Cook for 5-7 minutes or until the salmon is cooked through and flakes easily with a fork.
Stir in the baby spinach and cook until just wilted, about 1-2 minutes.
Remove from heat, then add the lime juice to brighten the flavors.
Serve over a bed of jasmine rice and garnish with fresh basil and cilantro.