Turn your Instant Pot onto Sauté on high. When the display reads HOT, add oil. When the oil is hot and shimmering, add the minced garlic and sauté for 30 seconds.
Add onions and ground beef. Stir while breaking up the ground beef clumps. Don't worry about cooking the beef at this stage, just break it up well. Note, if you have ANYTHING sticking to the bottom of the Instant Pot, pour in 1/4 cup of water and thoroughly deglaze the bottom of your pot.