– Place pasilla peppers and tomatoes in a saucepan and cover with 4 cups of water. Cook over medium-high heat for about 15 to 18 minutes until they are cooked and the peppers have softened.
– While the peppers and tomatoes are cooking, heat vegetable oil in a large frying pan over medium heat. Season steaks with salt and pepper, and add to frying pan once the oil is hot. Cook for about 6-8 minutes. Then add the potato cubes and stir. Keep cooking.
– The place already cooked tomatoes and peppers in your blender and add the chopped onion and garlic, plus 1 ¼ cup of the cooking water. Process until you have a very smooth sauce.
– Pour sauce unto the frying pan with the steak and potatoes, using a strainer. Season.
– with salt. Once it starts boiling, reduces heat to simmer. Simmer for about 10 minutes or until potatoes have softened.