Yields about 2 cups
4-6 tomatoes (choose a variety for best results, or use paste tomatoes), cut into chunks
½ medium onion, cut into chunks
1 celery stalk, cut into chunks
2-4 shishito peppers or 1 green bell pepper, cut into chunks
3 tablespoons good quality distilled cider vinegar
2½ teaspoons kosher salt, or to taste
1/8 teaspoon ground cloves
½ teaspoon cinnamon
¼ teaspoon ground mustard
1 teaspoon garlic powder
¼ teaspoon cayenne pepper
¼ teaspoon allspice
1. Combine the tomatoes, onion, celery stalk, and peppers in a food processor and process until pureed.
2. Transfer to a deep pot and bring to a boil. Once boiling, add vinegar, salt and spices. Turn heat to low and continue to cook until mixture thickens, stirring occasionally, about 1 hour.
3. Return mixture to food processor or blender and process until smooth, if desired. Strain mixture into a bowl, pushing it through the mesh with a spatula. Taste and adjust seasoning if necessary. Store in the refrigerator.