If you have a full heart on hand, make sure you cut it open and trim all the fatty and veinlike ventricles visible on the outside. Slice it into steak-like pieces. Otherwise you can simply ask to your butcher to clean and slice the heart.
In a large, deep bowl mix all the ingredients needed for the marination. Place the slices of heart into the bowl and let it marinate in the fridge overnight.
The next day, take the meat off the marination and pat it dry. Keep it in the fridge while you prepare the sauce and the potatoes.
Wash and scrub the skin of the potatoes. Slice them as you like, rinse and dry with a towel.
In a large bowl, mix the flour, cornflour, baking powder, salt, pepper, and sliced potatoes and give it a mix. Make sure the potatoes are coated with all the dry ingredients.
Preheat your oven in 200C/400F degrees. Place a baking paper on an oven tray and spread the coated potatoes in one layer. Pour the olive oil all over the potatoes equally.
Bake the potatoes for 30-40 mins until they are fully cooked and golden brown. In the middle of the baking, turn the potatoes inside out with the help of a spatula.
For the sauce, bring all the ingredients into a food processor except for shallot. Give them a mix until it becomes like a paste.
Finely hand-dice the shallot and mix it with the sauce.
It is now time to cook the heart. In a skillet, pour 3 tbsp olive oil and bring the heat on high. After the pan is hot, place the hearts and cook both sides for 4-5 minutes or until the skin is crispy and dark in color.
Let the meat rest at room temperature for 5 mins and then slice it into pieces. Serve the sauce on top of the meat and fries.