Chef John's Hearty Tuscan Bean Soup

Heat a generous amount of olive oil over an elevated heat setting in a substantial cooking vessel. Introduce butter into the pot and permit it to liquefy. Add sliced onions, chopped celery, and grated carrots, and cook while stirring until the onions start to transform into a golden hue and become translucent, approximately 7 minutes. Stir in minced garlic; cook for an additional minute. Introduce canned beans and broth into the pot, followed by a pinch of salt, pepper, dried rosemary, thyme, and cayenne pepper for added flavor. Set the heat to an elevated level and bring the mixture to a gentle simmer. Gradually reduce the heat to a lower setting and permit it to cook until the vegetables are tender, roughly 30 minutes.

Place bread cubes in a shallow sauté pan. Drizzle with olive oil and sprinkle a pinch of salt and pepper over the bread cubes for added flavor. Cook the bread cubes over medium heat, stirring occasionally, until they achieve a golden brown and crunchy texture, approximately 10 minutes. Sprinkle grated cheese over the bread cubes and continue to cook until they reach a desirable browning level, roughly 2 additional minutes.

Blend the soup with an immersion blender until it reaches a smooth consistency. Whisk in creme fraiche to enhance the flavor and texture of the soup. Stir in a squeeze of lemon juice for added brightness. Serve the soup hot, topped with browned bread cubes and a sprinkle of chopped parsley for garnish.