Heat olive oil in a medium stockpot over medium-high heat. Add onions and cook until they soften. Add the bay leaves, carrot, split peas, and water. Bring to a boil, then reduce to a simmer. Simmer for 25 minutes, or until the split peas have softened but still have a bite. Season with salt to taste. Add more water if the soup is too thick.
Puree the soup, reserving about ¼ of the soup for a chunkier consistency. Heat through, taste for salt.
Stir in lemon juice, if using, and a few grinds of black pepper. Serve.
If craving something a little different, feel free to add in a little curry powder, ground cumin or hot paprika just before adding in the split peas in step 1.