Preheat the oven to 200°C. Quarter the tomatoes, then arrange them on a sheet of baking paper in a shallow metal oven dish or cake pan. Drizzle with olive oil, and season with salt and pepper. Place them in the oven and cook for 30 minutes, or until the edges begin to caramelise and darken. Remove from the oven and cool to room temperature.
Drain the beans, then place them in a large bowl with the chopped olives, basil leaves and roasted tomatoes.
Measure the extra virgin olive oil, lemon juice, garlic and Dijon mustard into a small screw-capped jar or shaker, then shake to combine. Pour the dressing over the salad, then toss gently. Taste, and season with salt and freshly ground black pepper if required.
