Cook the green beans in boiling water for 3-4 minutes. They should still have some bite. Tip into a colander, refresh under cold water and drain.

In a small bowl, mix together the olive oil, vinegar, chilli flakes, salt & pepper. Set aside.

In a big serving bowl, add the rocket, baby spinach, watermelon, green beans, feta cheese and red onion, and combine well. Add the vinaigrette and toss. Adjust seasoning if necessary and garnish with the fresh mint.