Pour 1/3 cup olive oil into a deep pot, and heat over medium heat. Stir in the carrots, celery, and onion; cook until vegetables can be pierced with a fork, about 5 minutes. Stir in the portobello ..
Melt the butter in a medium saucepan over medium heat. Place leeks and garlic in the pan and slowly cook and stir 10 minutes, or until tender and lightly browned. Mix in the chicken broth and salt. Reduce heat and simmer approximately ..