Preheat oven to 218°C/425°F.
In large bowl you plan to serve the salad in, mix diced tomatoes and salt. Let rest for 15 minutes to draw out liquid. Meanwhile prep other ingredients.
Cut bread into relatively even, ½ inch pieces and place in bowl. Mix oil or butter with Italian seasoning and toss with bread cubes, distribute well. Toss on baking sheet and place in oven for 10-15 minutes until outside is crunchy and getting golden. A nice crunchy outside will prevent bread from getting too soggy. Remove from oven and let cool.
Prepare vinaigrette by mixing all ingredients in a small measuring cup. Pour over tomatoes, mixing in with the tomato liquid.
Add cooled bread, cucumbers, peppers, onions and basil to tomatoes and vinaigrette. Toss well.
Let rest for 15-20 minutes before serving to soften croutons slightly and let flavors blend.
