TOSS shrimp and chili sauce in medium bowl. Refrigerate 30 minutes.
BRING stock to boil in large skillet or wok on high heat. Add tomatoes, kaffir lime leaves, lemon juice and sugar. Reduce heat to low; simmer 8 to 10 minutes or until most of the liquid has evaporated. Stir in coconut milk; simmer 4 minutes. Add shrimp; cook 2 minutes or until shrimp turn pink. Season to taste with additional lemon juice or sugar. Or, add fish sauce to balance flavors. Remove kaffir lime leaves before serving.
GARNISH with green onions, if desired. Serve with cooked jasmine rice, if desired.