In a large sauce pot, heat the olive oil over medium heat. Add the celery, garlic, parsnip and onion, and saute for 15 minutes to build flavor, seasoning with salt and pepper as you go. Add the oregano, thyme and bay leaf, and cook on low for 3 more minutes. Turn the burner off and add the bourbon, return to the heat and reduce for 3 minutes. Add the split peas, ham and stock. Remember to season lightly as you cook. Cook until the peas are tender and the soup has reduced to the desired consistency, about 1 hour. Pull the ham piece and herbs from the pot and, using an immersion blender, blend the soup until mostly smooth. Cut the ham into 1/2-inch pieces and add back to the pot. Serve with the toasted baguette.