Heat your oven to 350 degrees. Slice the tomatoes in half, and place then on a baking sheet inside facing up. Drizzle with the olive oil, and sprinkle with salt, pepper, and the basil. Let roast in the oven for 15-20 minutes, until soft.

If you are not preparing this salad right away, pour the tomatoes and all of the juice in a container and keep in the fridge.

To assemble the salad, start by dividing the arugula on two plates, top with some mozzarella and the tomatoes. Spoon any extra juice from the tomatoes over the greens.