FOR THE SOUP
1 28-oz. can whole peeled plum tomatoes
2 tablespoons olive oil
1/2 teaspoon red pepper flakes
2 cloves garlic, minced
1 cup diced onion
2 1/2 cups low-sodium chicken stock
Kosher salt and freshly ground pepper

FOR THE CROUTONS
1/2 baguette, sliced (about 16 slices)
Olive oil, for drizzling
8 ounces fresh mozzarella, thinly sliced
Fresh basil leaves

1 28-oz. can whole peeled plum tomatoes 2 tablespoons olive oil 1/2 teaspoon red pepper flakes 2 cloves garlic, minced 1 cup diced onion 2 1/2 cups low-sodium chicken stock 1/2 baguette, sliced (about 16 slices) 8 ounces fresh mozzarella, thinly sliced

Directions

Pulse tomatoes and liquid in a food processor until chopped. Heat oil and red pepper flakes in a saucepan over medium heat. Add garlic and onion. Cook, stirring, until onions are tender, about 6 minutes. Add tomatoes and stock and bring to a boil. Reduce to a simmer and stir occasionally, until slightly reduced, about 30 minutes. Puree until smooth; season with salt and pepper.
Meanwhile, drizzle bread with oil. Toast in 375 degrees oven until it begins to turn golden, about 5 minutes. Top with mozzarella and return to oven. Cook until cheese begins to melt, about 1 minute more.
Top with fresh basil, season with salt and pepper, and serve with soup.