In a large skillet over medium heat, add 1 tablespoon oil, beef, and ½ teaspoon salt. Cook until beef is cooked through, breaking into small chunks as it cooks, about 5 minutes. Use a slotted spoon or spatula to transfer to a bowl, leaving about 1 tablespoon of oil behind.
If using another meat with less fat or veg option, add 1 tablespoon olive oil to the skillet. Add the onion and ½ teaspoon salt and cook until softened, about 3 minutes. Add the garlic, potatoes, bell pepper, and spices and cook for 30 seconds, stirring often.
Stir in the tomatoes, water, raisins, olives, cooked beef, and remaining ½ teaspoon salt. Use scissors to cut the tomatoes into small pieces/release their juices. Press everything down to try to submerge the potatoes in the liquid. Cover the skillet, increase the heat to high to bring to a rapid simmer, then reduce the heat to medium-low to keep at a rapid simmer for 15-20 minutes, stirring occasionally, or until potatoes are cooked through. Remove the lid, give it a stir and press down again into a compact layer, and let simmer for another 5 minutes to reduce the sauce a bit and continue to cook the potatoes.
Serve the picadillo in warm tortillas or on top of rice. Top with plenty of your desired toppings!