Sprinkle fish with 3/4 teaspoon curry powder, 3/8 teaspoon salt, and 1/8 teaspoon black pepper.
Heat a large nonstick skillet over medium-high heat.
Add oil to pan; swirl to coat.
Add fish; cook 4 minutes or until deeply browned on bottom but undercooked on top (fish will finish cooking later in sauce).
Remove fish from pan.
Add onion and bell pepper to pan; saut 4 minutes or until tender.
Add ginger and garlic; saut 1 minute.
Add remaining 3/4 teaspoon curry powder, remaining 3/8 teaspoon salt, remaining 1/8 teaspoon black pepper, tomato, and lemon juice. Reduce heat to medium-low, and cook 10 minutes or until tomato breaks down, stirring occasionally. Mash tomato with a wooden spoon.
Stir in coconut milk. Return fish along with accumulated juices to pan, browned side up. Reduce heat to low; cover and cook 8 minutes or until fish flakes easily when tested with a fork.
Cut fish into 4 equal portions. Spoon sauce into individual, shallow bowls; top each with a piece of fish.
Serve with lemon wedges and chopped fresh cilantro, if desired.