A short-cut for finely chopping vegetables: A food processor is a quick way to finely chop veggies. First, cut the onion, carrot and celery into large chunks. Put all of the vegetable chunks (plus whole cloves of peeled garlic) in the bowl of your food processor. Process until very finely chopped. 

1. Press the Instant Pot saute button, adjusting the heat level to "Normal." Add the olive oil. Saute onion, carrot, celery and garlic until soft and lightly browned, 5 to 7 minutes. 
2. Adjust the saute heat level back up to "More." Add the ground beef and pork, breaking up the meat with a spatula as it cooks. Don’t stir the meat too frequently, or it will take longer to brown. Season the meat with salt and pepper. Cook until the meat is no longer pink, 8 to 10 minutes.
3. The meat will release quite a bit of fat as it cooks. You can pour off some of the fat or just leave it all in the pot. Your choice. I've made it both ways, and both taste great but if you leave all of the fat in the pot your bolognese will have a noticeable amount of fat in it.
4. Add wine. Simmer rapidly for 2 minutes to evaporate the alcohol.   
5. Add tomatoes. Mix well.
6. Secure the lid. Make sure the steam release valve is in the sealed position. Cook on high pressure for 20 minutes. The Instant Pot will take 10-15 minutes to reach pressure before it starts cooking.
7. When the cooking time is done, manually release the pressure for a quick release.
8. Remove the lid. Stir the bolognese. Press the Saute button. Simmer the bolognese for 10 to 20 minutes, stirring frequently, to thicken the sauce.
9. Season with more salt and pepper to taste before serving. 
10. Serve the bolognese with a pound of your favorite pasta.