Step 1

Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 450 degrees. Wash and dry all produce. Halve tomatoes. Thinly slice mozzarella. Roughly chop walnuts.

Step 2

Place flatbreads on a baking sheet (divide between 2 sheets for 4 servings). Evenly spread tops with pesto.

Step 3

Top flatbreads with mozzarella and tomatoes. Bake until cheese has melted and tomatoes are softened, 8-10 minutes. (For 4 servings, swap rack positions halfway through roasting.)

Step 4

Meanwhile, in a medium bowl, whisk together half the vinegar (all the vinegar for 4 servings) and a large drizzle of olive oil.

Step 5

Add arugula to bowl with dressing and toss to combine. Season with salt and pepper.

Step 6

Top baked flatbreads with salad and sprinkle with walnuts. Drizzle with basil oil to taste. Slice into pieces and serve.