Remove skins and tendons from beef liver, then cut into strips. Zest the organic lemon and set aside. Squeeze the lemon and mix the juice with 2 tablespoons olive oil. Refrigerate the liver marinating in this mixture for 30 minutes.
Blanch the tomatoes in boiling water for 1-2 minutes, then transfer to cold water. Peel, remove seeds, and cut into pieces. Peel and crush the garlic cloves. Wash the parsley and mint, shake dry, and chop finely. Core the hot peppers and cut into narrow strips.
Heat olive oil in a large pan over medium-high heat. Fry the liver strips in batches for 3-4 minutes until browned, then set aside. If needed, add a little more oil to the pan. Reduce heat to medium. Sauté the tomato pieces with garlic for 1-2 minutes. Add the chopped mint, pepper strips, and most of the parsley (reserving some for garnish). Cook for 1-2 minutes. Season with Ras el Hanout, ground cumin, chilli flakes, salt, pepper, and a little cinnamon. Return the liver to the pan and heat for 1 minute. Sprinkle with lemon zest and reserved parsley.