In a large pot, warm the oil over medium heat. Add the leek, celery, and ½ teaspoon salt and cook until softened, about 5 minutes. Add the garlic, fennel seeds, oregano, and red pepper flakes (if using) and cook for 30 more seconds.
Stir in the potatoes, water, white beans, and remaining 1 teaspoon salt. Bring to a boil, then reduce heat to low and simmer for 7-10 minutes, or until the potatoes are cooked through (this will depend on how large you chopped them).
Stir in the fennel, snap peas, kale, and simmer for 3-5 more minutes or until tender. Turn off the heat and transfer about ½ cup of the broth to a small bowl. Add the miso paste and use a fork to mash/dissolve it. Stir it back into the pot along with the lemon juice
Serve topped with shredded parmesan or feta cheese and dill. Drizzle with olive oil and some black pepper, if you’d like (recommended!).