Toast the bread in a hot skillet with about 2 tbsp olive oil
Put the toasted bread cubes on the serving platter
Layer the bigger tomatoes next followed by the cherry and grape tomatoes, cucumbers, onions and finish with the fresh basil. Make sure to lightly salt and pepper the layers
Next make the vinaigrette
Whisk the mustards and vinegars with the seasonings.
Slowly whisk in the olive oil. The mixture should get thicker, but don’t get discouraged if it doesn’t. The flavors will still be great.
Alternatively you can put all the dressing ingredients in a mason jar and shake them all together.Pour the greasing generously over the salad. This can be made a few hours ahead, the flavors will only get better.