Roughly chop onion. Transfer bacon to a pot of water. Add chopped onion, bay leaves, peppercorns, cloves, salt, and some of the rosemary and thyme to the pot. Let simmer for 2 hrs. Meanwhile, add black beans to a pot of salted water and cook for approx. 20 min.
Thinly slice shallots. Add cane sugar, some butter, and shallots to a small saucepan and let shallots caramelize over medium heat. Add crushed garlic, some more rosemary and thyme sprigs, and deglaze with Port wine. Let reduce by two-thirds.
Remove peel from half of the lemons, then juice together with two-thirds of the pears. Strain juice through a fine sieve into a saucepan. Stir in agar-agar and bring to a boil. Season with salt and pepper, stir to combine, then strain into a bowl. Set aside and allow to cool. When the pear jelly is cooled down, transfer to a large liquid measuring cup, blend, and set aside until serving. Halve and juice remaining lemon. Cut the remaining pears into wedges, cover them with lemon juice, and set aside.
Pre-heat oven to 160°C/320°F. Lay out a piece of parchment paper and distribute Parma ham slices over it. Cover with another piece of parchment paper and transfer to a baking sheet. Cover with another baking sheet and bake for 8 – 10 min., or until crispy.
Add pistachios and white bread without crust to a blender. Season with salt and pepper, then blend for approx. 1 min. Transfer the pistachio mixture to a bowl, add soft butter, and stir to combine. Lay out a piece of parchment paper, distribute pistachio mixture over it, and cover with another piece of parchment paper. Thinly roll, then refrigerate. Remove Parma ham chips from the oven, transfer them to a paper towel and let drain. Set aside until serving.
Strain the boiled black beans, reserving the cooking water, and set aside approx. one quarter of them. Add the other three-quarters of the black beans to a blender, along with some of the cooking water to achieve desired consistency, and season with salt and pepper. Halve and juice lemon into it. Blend briefly, then add cold butter and blend for approx. 5 min.
Meanwhile, strain Port wine reduction through a fine sieve. Season to taste with salt and pepper and keep warm until serving. Once the bacon is cooked, remove it from heat. Slice bacon and keep it warm in its broth until serving.
Cut off the ends of the green beans, halve them and peel and thinly slice red onion. Core and finely dice tomatoes. Parboil green beans in a small saucepan with salted water. Heat oil in a small frying pan and add red onion slices. Transfer green beans to an ice bath. Add black beans, flageolet beans, and green beans to the pan. Season with salt and pepper. Add some butter and tomato dices and sauté briefly.
Heat oil in a large pan over medium-high heat. Add lamb fillet and sear on both sides. Transfer to the oven for approx. 5 min. at 160°C/320°F. Melt half of the remaining butter in a small saucepan, season with pepper and salt, and simmer pear wedges until softened. Melt the rest of the remaining butter in another large frying pan. Meanwhile, cut pistachio crust to fit lamb fillet. Transfer lamb fillet to the pan, fry again for another approx. 2 min., and add remaining rosemary and thyme sprigs. Crush remaining garlic clove and add to the pan. Season to taste with pepper and salt. Remove lamb fillet from the pan and top it with the pistachio crust. Distribute bean purée and pear jelly over a serving plate. Arrange beans, pear wedges, and bacon slices on the plate. Toast pistachio crust using a flambé torch and cut lamb fillet into pieces. Serve with ham chips. Garnish with cress and pour Port wine reduction over. Enjoy!