Lentil Soup with basil

1 (12 ounce) bag lentils , sorted and rinsed 2 lbs diced ham 4 stalks celery , thinly sliced 4 carrots , diced 1 medium onion , diced 8 -10 button mushrooms ,[...]

1 onion , chopped 1/4 cup olive oil 2 carrots , diced 2 stalks celery , chopped 2 garlic cloves , minced 1 teaspoon dried oregano 1 bay leaf 1 teaspoon drid[...]