In a medium-sized bowl, combine the shrimp with 1/2 teaspoon of salt. Set aside for 15 minutes. In a blender, blitz the chipotles, tomatoes and garlic. Set aside.
In a large flat-bottomed skillet. Warm the olive oil and onions over medium heat, cook until softened, about 5 minutes. Add the shrimp and cook for 3 minutes, stirring frequently. With a slotted spoon, remove the shrimp and set aside.
Pour the chipotle-tomato mixture into the skillet. Add the oregano, remaining 1/2 teaspoon salt and white wine. Stir to incorporate and simmer for 15 minutes. Add the shrimp and cook for an additional 5 to 8 minutes, or until the shrimp are entirely cooked.
Turn off the heat and add the fresh lime juice. Stir to incorporate. Taste and add more salt and lime juice, to taste. Serve the shrimp and chipotle sauce on top of cook rice. Top with toasted pepitas and fresh cilantro.