In a saucepan, combine diced Roma tomatoes, dried guajillo chiles, and enough water to cover the ingredients. Bring to a boil over medium heat, then let it simmer for about 10 minutes until softened.

Transfer the softened tomato and chile mixture to a blender. Blend on high until smooth, adjusting thickness with reserved cooking water if needed.

Pat the shrimp dry, season with lime juice, salt, and pepper, and let marinate briefly.

Heat a skillet over medium-high heat, melt butter, and add olive oil. Sauté the shrimp for about 1 minute per side until slightly translucent.

In the same skillet, reduce heat and add chopped onion, cooking for approximately 3 minutes until translucent. Stir in minced garlic and cook for an additional 30 seconds.

Pour the blended sauce into the skillet with onions and garlic, stir to combine, and simmer for 2 minutes. Add the shrimp back into the pan and cook until fully opaque.

Taste and adjust seasoning. Garnish with cilantro and serve immediately with lime wedges, rice, or warm tortillas.