Trim excess skin and fat from the chicken thighs.
Season the skin side of the thighs with 1 teaspoon salt, 1/2 teaspoon black pepper, 1 teaspoon paprika, and 1 teaspoon dried oregano.
Insert the stainless steel pot into the Instant Pot and select the Sauté function. Heat for 2–3 minutes.
Add 1 tablespoon olive oil and 1 tablespoon butter to the hot insert; when the butter is melted and sizzling, stir in 1 teaspoon minced garlic.
Place the chicken thighs in the pot skin-side down and brown for 2–3 minutes until golden and browned but not burnt; flip and brown the other side about 1 minute.
Press Cancel/Off and transfer the browned chicken to a plate.
Pour 1 cup water into the insert and use a wooden spoon to scrape up the browned bits from the bottom.
Place the trivet in the Instant Pot and arrange the chicken thighs on the trivet.
Close the lid, set the valve to Sealing, select Manual (or Pressure Cook) and set the time to 12 minutes.
When cooking is finished, let the pressure release naturally (at least 5 minutes), then carefully open the lid and transfer the chicken to a plate to rest.
Remove the trivet. In a small bowl, whisk 1 tablespoon cornstarch with 1/4 cup water until smooth.
Turn the Instant Pot to Sauté, stir the cornstarch slurry into the liquid, and simmer until the gravy thickens, stirring frequently; serve the chicken with the gravy.