Heat the oven to 350 F. Tear or dice the bread into 1” chunks. Drizzle liberally with olive oil and a pinch of salt. Toss to evenly coat, spread on a sheet pan, and bake for about 10-15 min. until lightly toasted. Set aside to cool.
Char the peppers on a grill or under a broiler until the skin is blistered. Transfer to a bowl and cover tightly with film wrap. When the peppers have softened and are cool enough to handle, peel off the skin, and remove the stems and seeds over a strainer set in a large bowl to capture all the juices. Discard stems, seeds, and skin. Dice the peppers into 1” chunks and add to the bowl with the juice.
Wedge or dice the tomatoes and add to the peppers. Season with a generous pinch of salt and pepper and add the garlic, red wine vinegar, more oil, basil, and red onion. Mix in the toasted bread and stir to coat. Allow to rest for ½ hour for the flavors to marry, then stir and add more oil, vinegar, salt & pepper as desired; the bread will continue to absorb the dressing. Add optional ingredients and serve with greens if desired.