Prepare the onions, garlic, celery, carrots, and pepper, and place in a large bowl.
Season the goat meat with salt and pepper. Add to the bowl. Toss well, cover with plastic wrap, and refrigerate for 2 hours.
Using the saute function, brown the meat and veggies in batches in the olive oil and butter. Remove to a large bowl as browned.
Add the stock and wine to the Instant Pot. Stir and scrape the bottom to release all the “goodies” that are stuck on the bottom. Add the tomato paste and stir to blend well.
Turn the IP off, add back the meat and veggies, combine thoroughly with the liquids. Place the top on turning to the locked position. Move the pressure knob to the closed position and set the manual timer to 25 minutes.
Allow the stew to Natural Pressure Release (NPR). This will take a few minutes.