Prepare the pressure canner and jars. Keep the jars warm until you're ready to fill them. Your pressure canner should be placed on the stove and filled with 2 inches (8 cm) of water, depending on the instructions of the canner manufacturer.
Heat the canner water to just barely hot, about 140 degrees Fahrenheit, on the stovetop while you're preparing your pot roast.
Combine all of the ingredients in a large bowl. Mix well.
Pack the jars with the mixture. Add hot water or broth to top them off.
Remove air bubbles, double-check headspace, then apply the lids and bands. Tighten the bands until they are fingertip tight.
Load the jars into the pressure canner.
Put the lid on the canner, then turn it to the locked position. Turn the heat on medium-high, then vent steam for 10 minutes.
Put the counterweight or weighted gauge on the vent, then bring the canner to a pressure of 10 lbs for a weighted-gauge canner or 11 lbs for a dial-gauge canner. (Adjust for altitude if above 1,000 feet in elevation.)
Process for 90 minutes (quarts) or 75 minutes (pints). Remember to adjust your timer if the pressure drops below 10 (weighted gauge) or 11 lbs (dial gauge).
When the canning time has finished, you may turn the heat off. Let the canner depressurize, then, five minutes after that, remove the lid.
Allow the jars to cool for 10 minutes, then remove them from the canner.
Let the jars cool for another 24 hours at room temperature.
Check the seals, label the jars, and put them in storage for up to one year.