In a large pot, heat the olive oil over medium high heat and add the onion. Cook for about 5 minutes to start to soften the onion, then add in the zucchini, garlic, rosemary, and sage. Cook for another couple of minutes, stirring often.
Add the alcohol and mix well, making sure to scrape any onion bits off the bottom of the pan. Let the alcohol burn off for about 3-4 minutes.
Next, add in the split peas, potatoes, and water, with about 1 tsp of salt to start. Bring to a boil, then cover the pot, turn the heat down to medium and cook for about 30-40 minutes until the potatoes and split peas are soft and tender.
Pour the soup into a blender in batches, and return it to a different pot to simmer and stay warm. Puree it until it’s nice and smooth, but a few chunks are ok too if you like the texture.
Taste and adjust salt and pepper as needed. Serve warm and get cozy.