Preheat your oven to 200C/390F fan / 220C/430F / gas mark 7.
Rinse the duck breasts and pat them dry; gently score the skin with around five slices diagonally across the breast (imagine where you are going to slice the meat once cooked), taking care not to slice through the fat layer. Season both sides with salt and pepper, rubbing into the skin. Lightly cover and set aside.
Now to the fondants: lay one potato down on its flattest side and slice off the ends where they approach the centre of the potato. Stand it up on one end and make sure it is relatively upright, adjust if necessary. Slice to remove the skin from the remaining sides of the potato to create a ‘peeled’ tower. Use this as a guide for the remainder of your potatoes until you have two-three per person. Season each side of the potatoes with a little salt and pepper in a bowl.
Slice the end of the garlic cloves, smash them with the back of your knife and remove the skins.
Heat 50g butter and 2 tablespoons olive oil in a saucepan over medium-high heat; stand the potatoes up in the pan, avoiding the central heat if you’re on a gas burner. Add in the smashed garlic and 2 stalks of fresh rosemary and the thyme. After 2-3 minutes, use tongs to check your first potato’s bottom. If it is nice and browned across the surface, turn the potatoes over and brown the other end. If the garlic begins to brown, set them aside temporarily.
Once the other ends of the potatoes have browned, turn off the heat;return the garlic to the pan and pour in some stock to cover just under 1” of the potatoes – they will absorb all this goodness! Set a timer for twenty minutes.
Cut your fennel and shallot lengthways through the centre and slice into thin wedges, and roughly chop your parsley leaves. In a bowl, add your salad leaves, fennel, shallot and parsley, and gently toss 1 tablespoon olive oil, 1 tablespoon apple cider vinegar, season with a large pinch of salt and pepper and set aside.
When that twenty-minute timer has gone off, reduce the temp. on the oven to 180C/350F fan / 160C/320F / gas mark 4. Place your duck skin-side down into a cold, dry frying pan and place over medium heat. This is not a steak – don’t go for a crazy high heat or you’ll end up with burned skin! As the fat starts to melt out of the breasts, use tongs to hold the breasts in place and carefully collect the fat.
After around 8-10 minutes, once the flow of the fat has slowed and the skin is a beautiful deep golden colour, add 2 stalks of rosemary to a far edge of the pan, turn the breasts meat-side down and place into the oven for 5minutes.
Wash and trim the asparagus,removing the woody ends. If the stalks are particularly thick, you can carefully slice them lengthways down the middle – ensuring they’re roughly the same thickness.
Remove the duck from the oven and check the temperature with a meat thermometer by guiding the end to the centre of the breast. You are aiming for approximately 57C/134F for medium; 54C/129F for medium-rare; remember your meat will continue to cook slightly while it rests. If the temperature isn’t quite there, place the duck back in the oven for 3 minutes, check again, then lightly wrap in foil and set aside to rest for 5 minutes, keeping the pan to hand.
Check your potatoes have softened by carefully piercing the middle of the thickest with a knife,which should glide through. Turn up the temperature of the oven up to 220C/430F fan / 200C/390F / gas mark 6 if you need a little more heat, or if they’re looking good, turn the oven off.
Place the duck pan over medium heat and add the asparagus and 1 tablespoon of butter. Season with salt and pepper; if the stalks are quite thick, you can carefully add a little stock to the pan to soften them more quickly.