Heat a skillet over medium heat. Add 1 tbsp olive oil, 2 tbsp garlic, 1/2 tbsp ginger, and 1 tbsp lemongrass. Sauté for 1 minute or until the spices are fragrant.
Stir in 4 oz red onions and continue cooking for 2 minutes.
Add 3 oz tomatoes and stir to combine.
Season the mixture with 1/2 salt, 1/2 tsp black pepper, 1/4 tsp cumin, 1/2 tsp ground coriander, 1/2 tsp paprika, 1/2 tsp turmeric, 1 tsp Dijon mustard, 1/2 tsp Cajun seasoning, 1/2 tsp chili powder, and 1 tsp brown sugar. Stir occasionally for 2 minutes.
Pour in 1 cup chicken broth and 1/2 cup coconut milk.
Add 20 oz salmon fillet, 1/2 tsp fish sauce, and 1 tbsp lime juice. Cook for extra 10 minutes. Flip the salmon halfway through to ensure they are cooked evenly.
Take off the heat. Garnish with 2 tbsp cilantro and 2 tbsp mint leaves. Serve hot over 3 cups of cooked rice.