3. Add the tomato paste to the pot and cook for 2 minutes while stirring. Stir in the chile purée, cooking for another minute. Add the diced tomatoes with their juice, the fish stock, half the basil, oregano and green onions. Bring the pot to a simmer, then cover and transfer the pot to the preheated 350-degree oven on the middle shelf. Allow the broth to cook until all the flavors come together, about 30 minutes, stirring occasionally. Adjust seasoning, adding salt if necessary.