Heat the olive oil in a large, heavy-based saucepan over a moderate heat.
Saute the red pepper, minced garlic and tomato for 3-4 minutes, stirring occasionally. Add the passata, sugar and vegetable stock, bring to the boil, then reduce to a simmer.
Simmer for 10-15 minutes until thickened. Remove the soup from the heat when ready and puree using a stick blender until smooth.
Pass through a sieve into a clean saucepan. Adjust the seasoning as necessary and keep warm over a very low heat.
When ready to serve, heat the olive for the croutons in a large frying pan over a moderate heat. Saute the cubed bread for 2-3 minutes, tossing occasionally, until golden brown all over. Remove from the heat and season well.
Ladle the soup into serving bowls and scatter a few croutons on the surface. Garnish with chopped chives, garlic cloves and a few chive stalks before serving.
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