In a medium mixing bowl, whisk together vinegar, olive oil, jalapeños, garlic, sugar, salt, pepper and oregano.
Add chicken to marinating container and toss to coat. Place chicken into the refrigerator for at least 30 minutes. (For a freezer meal, place chicken with marinade in freezer for another day.)
Peel (or not) and cut potatoes into cubes. Place in a bowl of water and aside for 30 minutes.
When ready to cook, dump chicken and marinade into Instant Pot.
Place trivet on top of chicken. Drain potatoes and place in Stainless Steel Steamer Basket with garlic (if using) and place basket on top of trivet.
Lock on lid and close pressure valve. Cook at high pressure (most machines default to high pressure) for 3 minutes.
When beep sounds, wait 10 minutes and then release the rest of the pressure.
Remove lid and place chicken on a plate. Select Sauté/Browning simmer for 5 minutes, or until liquid has reduced 50%.
While liquid is reducing, mash potatoes and then add milk and mash. Add salt and mix through. Add butter and combine. Taste and adjust as needed.
Stir in honey and return chicken to pot to coat. Simmer, about 2 minutes, or until glaze is thick.
Plate chicken and drizzle glaze. Garnish with chopped scallions.
Notes
Dark meat can be substituted for white meat. Add one minute cook time.All the garlic can be added to the marinade, if you prefer not to make garlic mashed potatoes.