Fill your water bath (a large stock pot or heat-safe container works well) and preheat your immersino cooker to 185°F.
Peel and chop your beets into bite-sized peices. Transfer to a sous vide bag or other sealable plastic bag, then add olive oil, salt, pepper, and quartered lime. Seal the bag and shake to mix the ingredients. Remove as much air from the bag as possible.
Immerse the bag in the prepared water bath, ensuring it's fully underwater. Use a wooden spoon or other weighted object to hold the bag down if necessary. Cook for 2 ½ hours.
While the beets cook, combine honey, paprika and cayenne pepper in a small bowl and whisk to combine. Set aside.
Carefully remove the bag from the water and use a fork to test that the beets are tender. If not, continue to cook until tender. Use a slotted spoon to transfer the beets to a serving platter, discarding the excess liquid in the plastic bag.
Drizzle the beets with the spicy honey mixture, chopped pistachios, fresh parsley, and additional salt and pepper. Serve while warm, or allow the beets to cool, depending on your preference.