Heat 4 tablespoons olive oil in a heavy pan. Sauté fennel, shallots, and mushrooms in the oil on medium heat until translucent (about 8 minutes).
Add the brandy, Pernod, truffle salt, Worcestershire, lemon zest, Tabasco, ground pepper, salts, and tomato paste into the pan. Sauté for 5 minutes more.
Add the tomato and celery soups, and cook over medium heat, stirring until the soup base is heated through.
Add milk and half & half and whisk until smooth and heated through. Do no boil. Fold in the crab and allow it to heat through for a few minutes.
Adjust seasonings and consistency to your liking by adding a bit more milk.
Just before serving, add another splash of brandy. Top with a dollop of creme fraiche, and sprinkle with fresh chopped chives. Serve immediately. (Makes 10 cups).