Pat Lamb leg dry with paper towels. Make slits into the meat using a sharp pointed knife. Insert garlic cloves into the slits.
Combine the salt, pepper and spices in a small bowl.
Rub all over the leg of lamb.
Heat 1 tbs oil and 2 tbs butter in a skillet over medium heat.
Sear the lamb leg on all sides until browned and sealed.
Set the Instant Pot on Sauté and add the other tablespoon olive oil and remaining butter.
Heat up for 1 minute.
Add the leg of lamb in the Instant Pot, brown it a bit more.
Take the lamb out of the Instant Pot. Add the chicken broth and use a wooden spoon to scrape the bottom of the Instant Pot to deglaze it and remove any browned bits of lamb.
Add your lamb leg back to the instant pot and slowly pour in the broth.
Put the lid on the Instant Pot and close the valve. Set the pressure cooker to Manual, high pressure, for 30 minutes.
When the pressure cooker is done let it release pressure manually for 10 minutes. Then release the remaining pressure.
Add the carrots and onion to the Instant Pot.
Put the lid back on and set the Instant Pot on Manual for 5 minutes. When it is done let the pressure release naturally for 5 minutes, then release the rest of the pressure.
Check the temperature of the lamb using an instant read thermometer. If it is 70 degree celcius, take the lamb and vegetables out and cover it with foil to rest.
You can set the Instant Pot on Sauté and allow the remaining juices in the pot to thicken slightly for 5 minutes. This will form your gravy.
Serve roast leg with carrots, onions and spoon gravy all over.
