Cut the tops off the beets, leaving at least 1" of stems, and wash well.
Pour 1 cup of water in the pressure cooker. Place a trivet or steamer basket in the pot. Add the beets.
Pressure on HIGH for 22 minutes. After 22 minutes, let the pressure come down naturally for 10 minutes. Carefully release any remaining steam.
Check for doneness by inserting a knife in the beet. It should go in easily. If they're not quite done, add 3 more minutes of cook time and quick release.
In a medium bowl, whisk together the vinegar, mustard, oil, salt, pepper and brown sugar until combined.
When the beets are cool enough to handle, peel off the skins with your hands, or rub a paper towel over the beet and they skins should rub off.
Cut the beets into wedges and toss in the vinaigrette. Sprinkle with blue or goat cheese. Serve warm or at room temperature.