1.Heat 2 tablespoons of oil in a pan on medium. Cook onion and garlic for 5 minutes, until softened. Add tomato and cook for 5 minutes, until collapsed.
2.Add stock, tarragon, lemon rind and chilli. Reduce heat to low. Cover and cook, stirring occasionally, for 30 minutes, until reduced slightly.
3.Meanwhile, preheat oven to 200°C (180°C fan-forced). Toss bread in remaining oil. Place bread in a single layer in a baking dish. Bake, turning once or twice, for 15 minutes, until golden.
4.Ladle soup into bowls. Season and top with croutons, cherry tomato and extra tarragon.