Heat oil in small skillet over medium-high heat until hot. Add onion; cook and stir 3 minutes. Add roasted peppers, olives and vinegar; mix well. Cook and stir 3 to 4 minutes or until onion is soft and liquid is evaporated. Remove from heat.
Place bread slices on ungreased cookie sheet. Broil 4 to 6 inches from heat for 4 to 6 minutes or until lightly toasted on both sides, turning once.
To serve, spread pepper mixture on toasted bread slices. Serve immediately.