Pour the remaining 1 tablespoon oil into the pot and heat over medium. Sauté the shallots until softened and translucent, 3 to 4 minutes. Add the tomato paste, cook until it darkens and begins to stick to the bottom of the pot, about 2 minutes. Stir in the puréed tomato mixture, coconut milk, chile and 1 cup water. Scrape the bottom of the pot with your spatula to remove any paste stuck to the bottom. Simmer, uncovered, to allow flavors to meld and sauce to reduce slightly, about 20 minutes. Season with salt.
