Heat the Instant Pot pot and put in a few tablespoons of oil. Once the oil is hot, put in one layer of eggplant slices. Do not mess with them until they are properly charred at the bottom. Without this char, you won't get the smoky taste you need. Once these slices char, they will shrink a bit and you can put in some more eggplant slices. At this point, you may need to put in more oil. Use a spatula and scrape up the char from the bottom as needed. This took me about 10-15 minutes.