Cook the beans in boiling salted water for 20 minutes until al dente, then rinse under cold water.

Blanch the tomatoes in the same boiling water for a few minutes, remove with a ladle, allow them to cool, remove the skin and cut the flesh into cubes.

Fry the onion rings glassy with the olive oil in a pan. Add the diced tomatoes and sauté a few minutes. Then add the beans and turn everything again a few minutes in the pan. Season with salt and pepper, sprinkle with parsley and serve immediately.