Add butter/olive oil, veggies and salt and pepper to large pot over medium heat until veggies are very soft, about 7-10 minutes.
Rinse dried split peas. Add to the pot with veggies along with a bay leaf and stock. Stir. Bring to a boil then cover and turn to low. Cook about 50 minutes, stirring occasionally. Remove bay leaf and purée soup.
Select your desired topping variations and enjoy!
To reheat: Thin as needed with additional stock or water. To freeze: Store 3-6 months in the freezer in an airtight container