1. Heat a flat griddle or a large, heavy skillet. Toast 5 large garlic cloves, unpeeled, turning once or twice until they are somewhat softened (they'll give slightly when squeezed) and browned in patches, about 8 minutes. Peel.
2. In same griddle or skillet, toast 4 large ancho chiles (2 oz total), cut open and seeded, in batches, turning and pressing with tongs until they are fragrant, pliable and have turned a brighter red, about 1 minute. Transfer chiles to a bowl of cold water and soak to soften, about 20 minutes. Drain.
3. Toast ,1/2 tsp cumin seeds, 5 whole peppercorns and 1 whole clove in a small skillet over medium heat, stirring, until fragrant, about 1 minute.
4. Combine spices, drained chiles, toasted garlic, 1 clove raw garlic, 1/2 cup water, 1 tsp cider vinegar, 1/4 tsp dried Mexican oregano, 1/2 tsp salt and 1/2 tsp sugar in a blender. Blend until smooth, about 2 minutes, adding more water, 1 tbsp at a time, only if necessary to help mixture blend properly.