Pepper the steaks on both sides, drizzle with 2 tablespoons of lemon juice and set aside, covered. Preheat the oven to 200 degrees. Heat 1 tablespoon of olive oil in a pan, stir in the ham and fry for 2 minutes. Mix in the mushrooms and parsley, continue to fry gently for 2 minutes. Salt and pepper, season with 1 - 2 tablespoons of lemon juice. Transfer to a wide baking dish. Place the marinated steaks side by side on the mushroom mixture. Braise in the preheated oven for about 20 minutes. After 10 minutes, turn the meat, season with salt and pepper, drizzle over 2 tablespoons of olive oil and 1 tablespoon of lemon juice.
To serve, cover the steaks with the mushroom mixture and sprinkle with parsley.