Tom's Tasty Tomato Soup with Brown Butter Croutons

INGREDIENTS

• 1 medium onion, thinly sliced
• 2 teaspoons kosher salt, plus more as needed
• Kosher salt and freshly ground black pepper
• 1 tablespoon sugar
• 1 cup water
• 1/4 teaspoon celery seed
• 3 garlic cloves, smashed with the side of a knife and peeled
• 4 slices european-style rustic bread, crusts removed, cut into 3/4- to 1-inch cubes (30 to 36 cubes)
• 1/4 teaspoon dried oregano or 1/2 teaspoon finely chopped fresh oregano
• 5 cups canned whole tomatoes in juice
• 3 tablespoons unsalted butter
• 1 tablespoon unsalted butter
• 1/4 teaspoon crushed red pepper flakes
• 1 tablespoon olive oil
• 2/3 cup heavy cream
• 1/4 teaspoon freshly ground black pepper, plus more as needed