In a small mixing bowl, combine the olive oil with the balsamic vinegar, mustard, minced garlic and a pinch of salt and pepper. Whisk well to create a smooth and creamy dressing.
To Make the Salad
Place the mixed greens in a salad bowl and top with the cucumber and strawberry slices.
Add the mozzarella balls. Drizzle with the dressing and serve at room temperature, garnished with fresh mint leaves.