Rach's slow-simmered dipping sauce is the perfect accompaniment to any food that could use a little tasty dunking.
Heat a saucepot or small Dutch oven over medium heat with EVOO. Melt butter into oil, and add onions, garlic, and salt. Cook until very soft but not browned, 5-6 minutes, then add stock and bring to boil, add puree and tomatoes, break up tomatoes, stir in basil and simmer at low bubble, 20 to 30 minutes. For a smooth dipping sauce, use immersion blender to puree.