Preheat the oven to 180 celsius (350 Fahrenheit) and toss the bread in a bowl with 1 tsp of the olive oil. Mix to combine and place on a baking tray lined with baking paper and bake for 10 to 15 minutes, or until golden. Set aside to cool.
To make the dressing combine the remaining oil, mustard, sea salt, pepper and white wine vinegar in a small bowl and whisk to combine.
Slice the tomatoes, or if you have cherry tomatoes, quarter, and arrange on a plate. Season with sea salt and black pepper. Tear the bocconcini and scatter over the tomatoes. Scatter with basil leaves and the cooled croutons. Drizzle with the dressing and enjoy immediately.