Remove the packaging from the cornish game hens. If there is a piece of paper stuck to them then run them under the water to remove the paper.
Place the trivet in the instant pot and add the chicken broth and the onion.
Combine the garlic powder, salt, pepper, sage, and rosemary then rub it on the game hens.
Place the game hens in the Instant Pot and add the fresh garlic cloves and bay leaves. Put the lid on, seal it and select high pressure for 33 minutes.
When the cooking time is complete let the Instant Pot sit and release pressure naturally for 10 minutes then manually release the rest of the pressure.
The cornish game hens will not get brown in the Instant Pot. If you want the skin brown, turn the oven broiler on high. Set the game hens under the broiler for 3 to 5 minutes until the skin is brown.
Notes
When you release the pressure from the Instant Pot, check the internal temperature with an instant-read thermometer. It should read at least 165°F. If it is lower then put the game hens back in the Instant Pot and cook on high pressure for another 5 to 10 minutes. If your game hens weigh more than 1-1/2 pounds, add 5 minutes to the cooking time from the very beginning.
If you have different sized Cornish game hens adjust the cooking time based on their weight. It will take 22 minutes per pound to cook frozen Cornish game hens.