In a large pot, heat 2 tablespoons olive oil over medium heat. Add the leeks and cook until softened, about 3 minutes. Add the potatoes and cook, stirring, until the potatoes just begin to brown, about 5 minutes. Stir in 4 cups water, the vegetable broth, paprika and 1 teaspoon salt, scraping the bottom of the pot. Bring to a simmer and cook for 15 minutes. Lightly smash the potatoes, stir in the salmon and simmer for 5 minutes. Stir in the spinach and parsley and season with salt and pepper.
Meanwhile, preheat the broiler. Toast the baguette slices and brush with olive oil. Serve with the chowder.