Cook the frozen beans in little boiling salt water for about 8 minutes.
For the tapenade, finely chop the olives. Wash, quarter, seed and dice the tomatoes. Peel and finely dice onion. Mix the ingredients for the tapenade. Season with lemon juice, mustard, salt and pepper.
Stir in the oil.
Drain the beans and let them drain. Serve with the tapenade.