Rinse the beans in a sieve and let them drain. Peel and chop the onion. Clean the chillies, cut lengthwise, remove seeds, wash and cut into fine rings. Fry everything in hot oil. Stir in tomato paste, sweat briefly.
Add the tomatoes and bring to the boil. Simmer open over medium heat for 5-10 minutes.
Warm the beans in the sauce. Season with Worcester sauce, salt and pepper. Wash the chives, shake dry and cut into small rolls. Toast the bread. Pass the beans to the bread, sprinkle with chives.