Add the oil to your Instant Pot and turn on to “sauté”. Once the pot is warm, add the onion and apple (place both cut-side down), ginger, cardamom, cinnamon stick, star anise, and cloves. Sauté the food until slightly charred, approximately 4 minutes.
Turn off the Instant Pot. Without removing anything, add the beef bone broth, chicken stock, fish sauce, sugar, and salt. Place the lid on the Instant Pot and select Soup/Broth for 20 minutes.
While the broth is cooking, prep your toppings.
When the Instant Pot is done, let the pressure naturally decrease for 10 minutes. After 10 minutes, release the pressure and carefully open the Instant Pot.
Using a slotted spoon remove everything from the pot except for the Pho broth. Once everything is removed, put the philly sliced steak into the Pho broth to cook. Stir the steak slices while in the broth. The philly sliced steak needs to be thin to completely cook. If you have thicker steak slices, simple turn on the slow cook setting on the Instant Pot and let the broth cook the meat until it is done (depending on the thickness of the slices).
Put your toppings in a bowl and top with the Pho broth and steak. Squeeze a little lime on top and serve.
Notes
Suggested toppings for soup: bok choy, rice noodles (cooked according to directions), fresh herbs (basil, cilantro, or mint), sliced radishes, sliced mushrooms, sliced carrots, mung bean sprouts.