Heat the oil in a large skillet over medium-high heat. Meanwhile, toss the shrimp with the salt and half of the garlic. Add the shrimp to the hot oil and sauté until the shrimp is pink and curled, about 4 minutes. Use a spatula to transfer the cooked shrimp to a plate. Set aside.
¼ cup olive oil, 1 tsp Kosher salt, 4 cloves garlic, 20 large shrimp
Add the onion to the skillet (there should still be oil in the pan, add a little more, if necessary). Sauté until soft, about 4 to 5 minutes. Add the remaining 2 cloves of minced garlic and cook for another 30 seconds, stirring often.
½ cup white onion
Stir in tomatoes, sugar, salt, and bay leaves and bring to a boil.
1 28 oz. can diced tomatoes, 1 tsp sugar, 1 tsp Kosher salt, 2 fresh bay leaves
Reduce heat to medium-low and simmer, uncovered, stirring occasionally, until most of the liquid is evaporated, about 15 minutes.
Add olives, raisins, capers, and oregano to sauce and cook, stirring, for about 1 minute. Stir in the cooked shrimp. Cover the pan, and keep on very low heat while you prepare the tortillas.
½ cup green olives, ¼ cup raisins, ¼ cup capers, 2 tsp oregano