In a large pot or Dutch oven, add the butternut squash, carrots, potatoes, celery, green lentils, yellow split peas, onion, and garlic.
Pour in the vegetable or chicken broth, sprinkle in the herbes de Provence, and season with salt.
Bring the mixture to a boil, then turn the heat down to medium low and put the lid on. Simmer for about 40-45 minutes, or until the vegetables and legumes are tender.
Once cooked, take about 4 cups of the soup and put in a blender with the olive oil. Blend until it reaches a semi-smooth, creamy consistency. Return this mixture to the pot or Dutch oven.
Stir in the chopped kale and parsley, then turn off the heat. Allow the soup to sit for a few minutes for the flavors to meld.
Adjust the flavor with a swish of sherry, red wine vinegar, or lemon juice. Serve warm a sprinkle of Parmesan cheese, if desired.