Melt the butter on Saute-High mode in the Instant Pot insert. Once melted, saute the chopped onion and minced garlic for 2 minutes. Add the rice and saute for 1 minute. Toss the rice once or twice while it is toasting in the butter.
Turn off the saute mode and quickly pour in the white wine, chicken broth, and fresh chopped parsley. Stir to combine. Put the lid on, set the valve to sealing and cook on High Pressure for 6 minutes.
Quick release the pressure, remove the lid, and stir in the grated Parmesan cheese. Remove the insert from the base, and let cool slightly before serving. Season with salt and pepper to taste.