Place leek with 2 tablespoons of water and olive oil in a sauté pan. Cook covered for 5 minutes of medium heat or until the water has evaporated and you can hear the pan sizzle. Add the butter, fennel, artichoke hearts, 2 anchovy filets, orange juice, mustard, garlic and herbs de Provence. Mix well and cook for 2 minutes.

Place fish filet over the vegetable mix in the pan, cover and cook for 5 to 7 minutes, uncover and check if the pan juices have dried out. Add 2 tablespoons of orange juice if so. Also check if the fish has been fully cooked, if not, cover the pan and cook 2 minutes more.

Mix yogurt and 1 anchovy filet and a pinch of herbs de Provence. Plate on one side of the filet.

Place the thinly sliced potatoes in a serving baking pan, like a tiny casserole dish. Add water only to slightly cover them, bring to a boil, cover and cook for 2 minutes. Add the butter and 1 tablespoon of the yogurt herb anchovy mix over the top and broil for 5 minutes.

Remove the pan from the heat, plate, serve the remaining yogurt on the side and place the remaining 2 anchovy filets over the tilapia.