Heat oil in a saucepan over medium heat. Add onion and cook for 3 minutes or until translucent. Add carrots and celery and continue cooking 3 more minutes. Add split peas and stir well to coat.
Add beer to saucepan and reduce by half. Add chicken broth, orange juice and bay leaf. Bring to a boil then reduce heat to medium-low. Simmer uncovered for 45 minutes or until peas are tender but do not break apart.
Stir in orange zest. Remove bay leaf and serve in bowls or pretty mugs. Garnish with an orange slice.