In a large Dutch oven or soup pot, heat the oil on medium heat. Add the onions with a pinch of salt and cook, stirring, for 5 minutes. Then add the garlic with some more salt (to taste) and cook another 5 minutes, stirring often. Add the celery and carrots and sauté for about 4 more minutes. Add the curry powder, turmeric, and black pepper and cook for 1 to 2 minutes, stirring constantly. Add the potatoes, stock, and sherry or wine.

Cover and bring to a boil; then reduce the heat and simmer until the vegetables are very tender, about 15 minutes. Rinse the fish fillets and cut them into bite-sized pieces. Add them to the pot, cover, and cook for 5 to 7 minutes, until the fish is no longer translucent. Remove from the heat.

In the meantime, use a blender to puree the cream cheese and milk or half-and-half. Add some of the soup and puree. Stir the puree back into the soup. Taste for salt and pepper--or lemon juice. Add the peas and heat through gently before serving.