Heat a dutch oven over medium heat. Add the butter and heat until it foams. Add onions, carrots and celery and saute, stirring occasionally, until soft, 7-8 minutes.
Add the garlic and saute, stirring continuously, until the garlic is fragrant, about 1 minute.
Add the butternut squash, leeks, tomatoes, bay leaf, fresh thyme, salt, pepper, parmesan cheese rind, and broth to the pot and give everything a good stir.
Increase the heat to high and bring to a boil. Reduce to low, cover, and simmer until the squash is tender, 35-40 minutes.
While the soup is simmering, prepare the swiss chard and parsley.
Add the swiss chard and white beans to the pot, stir, and simmer until the chard is tender, 5-7 minutes.
Taste for seasoning and add additional salt and pepper if needed.
Fish out the bay leaf and fresh herb stems. Remove from heat and stir in the lemon juice and parsley.
Ladle into bowls, drizzle with about a teaspoon of olive oil, then sprinkle with parmesan cheese. Serve immediately. This keeps in the fridge for up to a week, or in an air tight container in the freezer for up to 3 months.