Peel and thinly slice an onion and load into the instant pot with extra virgin olive oil and sauté.
Season your lamb shanks with salt, pepper, and bouquet garni. Load into the instant pot and brown all sides of the lamb shank in the olive oil and onions.
Once browned cancel sauté and remove the lamb shanks and put to one side.
Deglaze the instant pot with red wine. Do this by pouring your red wine into instant pot cooking pot and then using a silicone spatula or a wooden spoon to scrape the brown bits and any oil or onion that is stuck in the bottom of the pot.
Peel and dice carrots. Clean and dice celery. Load celery and carrot into the instant pot.
Stir in tinned tomatoes, garlic powder, salt, pepper, and stock and mix well.
Submerge the lamb shanks.
Place the tall trivet over your lamb shanks and add your steamer basket.
Dice your potatoes and load as many potatoes as will fit without going passed the max line of the instant pot.
Season potatoes with salt.
Place the lid on the instant pot and cook for 60 minutes on meat/stew. When it beeps manually release pressure.
Remove the steamer basket and the trivet. In a bowl load up your potatoes and mash with a masher. Add in salt, pepper, thyme, butter, and milk.
Load the mashed potatoes onto a dinner plate and place a lamb shank on top.
Add a couple of tablespoons of mashed potatoes to what is left in the bottom of the instant pot and blend. The mushy vegetables and mashed potatoes and stock have now made a thick flavoursome lamb gravy. Pour a little gravy over your lamb shanks and then when cool portion up the rest for the freezer.