To make the curtido, combine all the ingredients in a large bowl and toss thoroughly. Set aside and allow the curtido to sit for at least half an hour before serving.
To make the salsa, boil the tomatoes with the dried chiles de árbol (if using) in a small pot of water until cooked through, about 10 minutes. In a small saucepan, fry the onion and garlic in a half tablespoon of oil over medium heat for about 3 to 4 minutes, or just until they begin to get some color.
Add the onion and garlic to a blender along with the tomatoes, chile de árbol, seasonings, and a quarter cup of the reserved cooking water. Blend until completely smooth.
Heat the remaining oil in the saucepan and fry the salsa until it has turned a deep red color, about 10 minutes. Check for seasoning and add more of the reserved cooking water if needed. Set aside.
To make the yuca, combine the water, salt, and garlic cloves in a large pot and bring to a boil. Add the chopped yuca once it reaches a boil, reduce to a simmer, and cook for about 20 minutes or until the yuca is tender when pierced with a fork.
Once tender, heat 2 cups of oil in a large pan over medium-high heat and fry the yuca in batches until golden brown and crispy on the outside, about 5 to 6 minutes per side. Drain on paper towels and continue until all yuca is fried.
In a separate skillet, fry the pepescas in the remaining oil for about 6 minutes or until golden and crispy, stirring occasionally.
When ready to serve, plate the yuca frita with the pepescas, top with curtido and salsa, and enjoy.