Tear all the chiles into large pieces and toast them in a large dry skillet over low heat until they start to brown, turning regularly to prevent burning, about 2 minutes. Add the oregano and continue to toast for 2 to 3 minutes until everything is fragrant. Remove from heat and cover chiles with boiling water. Weigh down with a small plate to keep them submerged. Soak until soft, at least 10 minutes. Strain and cool.
Preheat the broiler. Put the quartered tomatoes, sliced onion, jalapeno, and whole garlic cloves onto a parchment lined baking sheet in a single layer. Drizzle with plenty of olive oil and season well with salt and pepper. Broil until everything begins to char, about 15 minutes. Remove from oven.
Place roasted vegetables, strained chile peppers, and fresh cilantro in blender and purée until smooth. Add additional salt, if desired. Transfer to a serving bowl and serve.
Make about 1 cup. Easy to double recipe if more is needed.