
Add the guajillo and árbol chiles to a medium skillet over medium heat. Toast until fragrant, flipping occasionally, about 1 minute. Transfer to a small pot.
Add the tomatoes and fill the pot with water until the tomatoes are completely covered. Bring to a boil over high heat, reduce the heat to low, cover, and simmer for 2 minutes. Remove the pot from heat and let sit for 5 minutes to soften and rehydrate.
While the chiles and tomatoes are soaking, heat the olive oil in the same medium skillet over medium-high heat. Add the onions and garlic, and cook for 5 minutes, stirring occasionally. Remove from the heat and transfer to a large blender.
Add ½ cup of the chile cooking water, the rehydrated chiles, salt, and oregano to the blender. Blend until smooth.
Add the cooked tomatoes and pulse a few times for a chunky and rustic sauce, or blend completely for a smooth sauce. This is all personal preference.
Pour the sauce back into the same medium skillet and cook for 1 minute over medium heat, stirring often, then reduce the heat to low.
Use a spoon to make 4 small wells in the sauce and crack an egg into each well.
Cover and cook for 7-10 minutes until the egg whites are no longer clear and the yolks are cooked to your liking.
Garnish with desired toppings and with warm flour tortillas or toast.