Soak the dry shiitake mushrooms overnight in room temperature water. If rush on time, soak in warm temperature water until the mushrooms are soft and tender. Pre-boil the bones and brisket: add the bones and brisket to a large stockpot and cover with water. Bring the water to boil over high heat, then reduce to medium and simmer for 10 more minutes. Rinse the bones and meat over room temperature tap water.* Set aside. Discard the broth. Grill the ingredients under “Pho Aroma Combo†in a cast iron over medium heat. No oil added. Rotate and flip the ingredients frequently until you can smell a nice and lovely fragrant. Be careful not to burn the aroma combo. Slightly charred outer surface is okay but not burnt. Slice the mushrooms. Save the mushroom water. Roughly dice leek. Add aroma combo and leeks to large tea bags or cheesecloth tied with a string.* In a 6-quart size instant pot, add beef bones, brisket (fatty side up)*, diced carrots, aroma combo and leeks (in tea bags). Strain the mushroom water as you add the liquid to the pot. Fill the pot with more tap water until it reaches the 4 liter mark. Close the lid in Sealing position - Press Soup - Adjust to 40 minutes/High pressure/More. Allow the instant pot come to natural pressure release (valve dropped), discard the whole onion and aroma combo in tea bags. Remove the brisket and soak it in cold water for at least 10 minutes. This will prevent the meat from turning dark color. Discard aroma & leek tea bags, yellow onion, and beef bones. Season the broth with 2 ½ tsp fine sea salt, 1 tbsp fish sauce, and 1 tsp five spice powder (optional). Thin slice the brisket in 45 degree angle and against the grain. Ladle the broth over bean sprouts, carrots, mushrooms, mint leaves, Asian basil, chili peppers, and sliced brisket. Serve hot with lime wedges.