Sauté Aromatics: In a large skillet or wok, heat olive oil over medium heat. Add chopped onion and sauté until translucent, about 3-4 minutes.
Add Garlic and Ginger: Stir in minced garlic and grated ginger, cooking for an additional 1-2 minutes until fragrant.
Incorporate Curry Paste: Add red curry paste to the skillet, stirring to combine with the aromatics. Cook for 1-2 minutes to release flavors.
Add Vegetables: Introduce sliced red bell pepper to the skillet, cooking for 2-3 minutes until slightly tender.
Pour in Coconut Milk: Slowly pour in the coconut milk, stirring to combine. Bring the mixture to a gentle simmer.
Season the Sauce: Add fish sauce (if using), brown sugar, and lime juice. Season with salt and pepper to taste. Let the sauce simmer for 5 minutes to meld flavors.
Cook Shrimp: Add the peeled and deveined shrimp to the skillet. Cook for 3-4 minutes, or until the shrimp turn pink and are cooked through.
Garnish and Serve: Remove from heat. Garnish with chopped fresh cilantro. Serve hot over steamed jasmine rice.