Fattoush With Country Bread

Name: Fattoush With Country Bread
Ingredients: 3 slices country-style bread (or 4 rounds of day-old pita bread to make Fattoush With Pita Bread); 2 tbsp olive oil; 1 tbsp sumac; 2 tbsp warm water; 2 tbsp red wine vinegar; 1/4 cup olive oil; 1/2 tsp sea salt, plus more as needed; Ground black pepper; 2 red or yellow bell peppers, cut into 1/2-inch pieces; 1/2 red onion (or 1/4 if large), cut into 1/2-inch slices; 3 tomatoes, cut into 1/2-inch cubes; 4 or 5 small Persian cucumbers, cut into 1/2-inch cubes; 5 radishes, very thinly sliced; 1 bunch mint, coarsely chopped