What You Need
Make the soup:
In a HexClad 5 QT Dutch Oven, heat the oil over medium-high heat. Add the onion, carrot, and celery. Season with salt and pepper. Cook until lightly golden, 5 to 6 minutes. Add the cherry tomatoes, garlic, and crushed red peppers and cook until fragrant and cherry tomatoes begin to pop, 4 to 5 minutes more. Stir in the crushed tomatoes, broth, and sumac.
Meanwhile, make the sandwiches:
In a medium bowl, stir together the cottage cheese mozzarella, cheddar, dill, and garlic to combine. Season with salt and pepper. Spread cottage cheese mixture on half of the slices of bread and sandwich with the other slices.