Heat olive oil in a large saucepan over medium heat. Add onion and carrot; cook and stir until slightly softened, about 5 minutes. Stir in thyme. Pour in fish stock.
Stir smoked haddock into the saucepan; cook for 5 minutes. Transfer to a plate using a slotted spoon. Add potatoes to the saucepan; cook until tender, about 15 minutes. Return the haddock to the saucepan. Pour in cream and cook until heated through, about 5 minutes.
Season chowder with salt and pepper. Garnish with parsley.