Place the extra virgin olive oil, vinegar, lemon juice, salt and pepper in a small mixing bowl and whisk well. Check for seasoning and set aside.

Peel the celery, slice thinly and place in a large salad bowl.

Slice caciotta into cubes and add it to the bowl along with walnuts and grapes.

Add the dressing and toss to coat. Finish with fresh mint and serve.