Preheat oven to 350°F.
Preheat a flame grill over high heat.
Roast green pepper over open flame until charred on all sides. Place pepper in a bowl, then cover with plastic wrap and set aside for 4 minutes. Remove burnt skin, stem and seeds.
Cut 2 slices of bread into 1-inch cubes. Arrange on a baking sheet and toast for 3 to 5 minutes, turning often, until just crisp on the outside but soft on the inside. Set aside.
Place the roasted green pepper and all remaining ingredients, including the remaining 2 slices of bread, into a blender and blend until combined. If needed, adjust seasoning.
Chill soup in the fridge for at least 2 hours. Soup can be made the day before serving. Croutons can be stored in an airtight container until ready to serve.