Preheat dutch oven or other large pot on the stovetop over medium-high heat.
Add about 1 tablespoon olive oil to the pot. Add onions, and cook until the onions become soft, stirring occasionally.
1 onion, 1 tablespoon olive oil
Add the other vegetables, white wine, stock, seafood seasoning, thyme, salt, Worcestershire, and Tabasco. Stir to combine.
1 cup diced carrots, 1 cup chopped celery, 2 cups peeled and diced potatoes, 1 can corn, 1 bunch thyme, 2 cups white wine, 4 cups seafood or vegetable stock, 2 tablespoon seafood seasoning, ½ teaspoon kosher salt, 2 dashes Tabasco sauce, 2 dashes Worcestershire sauce
Bring the soup to a boil. Reduce to a simmer, cover, and cook for about 15 minutes.
Bring the soup back to a boil.
Combine the cornstarch with cold water and stir into soup. Add fish and shrimp. Reduce to low, cover, and simmer for about 15 minutes, stirring occasionally, until the fish is cooked through. The chowder will also begin to thicken.
Stir in cream and continue cooking on low until the soup is hot again after adding the cream.
1½ cup heavy cream
Notes
If using leftover cooked fish and shrimp instead of raw, add closer to the end of the cooking time in step 6 and cook until the fish and shrimp and heated through.