Heat 2 tablespoons of the extra-virgin olive oil in a large pot over medium heat.
Add the chopped onion and cook, stirring occasionally, until translucent, about 5 minutes.
Add the chopped garlic, coarsely chopped fennel, chopped carrots, and fresh thyme leaves. Stir and cook until the carrots begin to soften, about 10 minutes.
Stir in the balsamic vinegar, the 3 jarred roasted red bell peppers, the drained and rinsed cannellini beans, tomato paste, vegetable broth, and 1/2 teaspoon of the sea salt. Bring to a simmer and cook until the carrots are tender, 15 to 20 minutes.
Remove the pot from the heat. Working in batches if necessary, transfer the hot soup to a high-speed blender. Add the remaining 2 tablespoons of extra-virgin olive oil to the blender. Blend until smooth, taking care to vent the blender lid slightly or pulse to avoid steam pressure.
Return the pureed soup to the pot and reheat gently if needed. Taste and season: add up to an additional 1/2 teaspoon sea salt if desired (to total 1 teaspoon if needed), add the 1/2 teaspoon freshly ground black pepper, and stir in 1/2 teaspoon red pepper flakes if you want heat. If you want more acidity, add a few drops of balsamic vinegar to taste.
Ladle the soup into bowls. Top each bowl with the diced jarred roasted red pepper, a drizzle of extra-virgin olive oil, finely chopped parsley, pinches of red pepper flakes as desired, and microgreens. Serve with warm baguette.