Put the sweet potato cubes in the Instant Pot trivet along with the water. Close, ensure vent is sealed and program for 8 minutes on High Pressure. When complete, do a quick release and drain contents using a colander.
Keeping the Instant Pot on Warm (the default setting after cooking) add the butter to the Instant Pot insert to melt. Stir in the adobo sauce and return the drained sweet potatoes to the instant pot. Using a potato masher, mash the potatoes and stir to combine the butter and sauce. Salt to taste and serve warm. The potatoes may be left in the Instant Pot on warm until serving.