Blanch the green beans in a saucepan of boiling water for 3–4 minutes until just tender. Drain, rinse with cold water and drain again.
Put the beans, lettuce, onions and tomatoes into a large salad bowl. Lift the peppers out of the jar, reserving the oil, dice if needed and add to the salad.
Pour 2 tablespoons oil from the pepper jar into a frying pan, add the chicken and fry for 8–10 minutes, stirring until golden and cooked through. Spoon over the salad. Heat 1 tablespoon extra oil in the pan, add the breadcrumbs and anchovies, and stir-fry until golden.
Mix the dressing ingredients together, toss over the salad, then sprinkle with the breadcrumbs and anchovies and serve immediately.