Heat salsa in a pan or in the microwave until warmed. Serve with fried fish. If you'd like to make your own marinara sauce, here's a quick recipe: Heat 2 tablespoons olive oil in a saucepan over medium heat. Add 1/2 cup diced onions and sauté until lightly browned. Add 1 garlic clove (minced) and sauté until fragrant. Add 150 ml tomato paste and cook until it changes color. Add an 800-gram can of diced tomatoes and simmer over low heat, stirring occasionally, for 20 minutes or until it thickens slightly. Season to taste and add chopped basil.use the sauce as is or puree until smooth.