Heat olive oil in a large pot over medium-high heat. Once the oil is hot, add shallot, onion, carrots, and celery. Season with salt and pepper. Sauté, stirring occasionally, until the vegetables have softened, about 5 minutes. Stir in garlic and cook until fragrant, about 30 seconds to 1 minute.

Stir in tomato paste, cooking for another minute or two. Add beans, 3 cups broth, 1/2 tsp salt, 1/2 tsp pepper, Italian seasoning, bay leaves, and red pepper flakes. Stir to combine and bring to a boil. Reduce to a simmer over low heat. Cover and simmer for another 10 to 15 minutes.

Remove bay leaves and discard. Add about 3 cups of the soup to a blender and blender until smooth. Return the blended soup to the pot and stir to combine. If the soup is too thick, add in more broth until it is your desired consistency. I usually add another 1/2 cup to 1 cup.

Stir in kale and cook for several minutes, until it wilts.

Remove from heat and taste. Season with salt and pepper, as desired. Add some lemon juice, if desired. Serve.