Remove the butcher twine from the neck roasts and discard, rinse the roast and pat dry.
Drizzle oil into Instant Pot® (IP) and press “Sauté.” (Mine is a six quart brand name Duo model.)
When oil is shimmering, add the lamb. Brown on all sides (when brown the meat will release easily from the pot). Remove from pot to a plate while you continue with the recipe.
To the pot, add carrots, celery, onions, and garlic. Sprinkle dried thyme, salt and pepper over and sauté and stir till veggies are coated with the oil and are heated. Stir in the bay leaf. As the veggies release their liquid, scrape up the bits of browned beef from the pot. A wooden spoon is good for this.
Clear a space in the center of the pot and add the tomato paste. Continue to sauté till the tomato paste is bubbling, and then stir it into the vegetables.
Add the dry red wine and soy sauce and stir to combine with the vegetables. When the mixture comes to a boil, stir while simmering rapidly for 3 minutes to cook off some of the alcohol.
Add the bouillon and water (or broth/stock) and bring back to a boil.
Return the meat to the pot. Lock the cover and set to high pressure. Set timer for 75 minutes. Allow the pressure to release naturally, about 30 minutes. Meat should be tender when pierced with a fork. If not, cook for another 10 minutes under pressure and allow natural release for 10 minutes, then quick release.
Remove the roast to a platter to allow to cool till you can handle it.
Meanwhile, skim the fat off the broth in the IP. (Important step)
Taste for seasoning and add salt and pepper as desired.
Bring to a simmer and thicken with a slurry made from 2 tablespoons of cornstarch mixed with enough water to make a loose paste. Simmer till clear and glossy. Turn off IP and cover with lid to keep warm.
Pull the meat from the bones and stir the meat into the vegetables and sauce. Serve over rice, mashed potatoes, or noodles and enjoy!