Heat the oil in a cast-iron skillet set over medium heat.
Add the onion and sliced bell pepper, and saute until soft, about 10 minutes.
Add the minced garlic, cumin, paprika, and salt; cook for 2 more minutes.
Stir in the chopped tomatoes and canned tomatoes. Reduce the heat and stir to combine.
Simmer the sauce for about 10 minutes, or until it thickens.
While the sauce is simmering, preheat the oven to 375°F.
Remove the skillet from the heat, and use a large spoon to make 3 to 4 wells in the sauce. Carefully crack eggs into each well, and add mozzarella cheese over the Shakshuka, if using.
Transfer the skillet to the oven, and bake until egg whites are set but yolks are still slightly runny, about 10 to 15 minutes. Check often because the eggs can cook very quickly.
Take the baked shakshuka out of the oven, drizzle with olive oil, and season with salt and pepper. Garnish with parsley, jalapeno, and feta.