Prepare the Noodles: In a large bowl, cover the dried rice noodles with warm water and soak them until the noodles are pliable and opaque, 30 to 45 minutes. Drain the noodles and rinse them in cold water to remove excess starch.

Make the Broth: Select the Sauté setting on the Instant Pot and, after a few minutes, add the oil. Once the oil is hot, add the onions and ginger, cut side down. Do not stir them, but allow them to cook until charred and deeply browned, about 4 minutes.

Add the cardamom pods, star anise pods, cloves, cinnamon stick, coriander seeds, fennel seeds and peppercorns, and cook for 1 minute, stirring the mixture frequently. Add the apple, cilantro, tamari or soy sauce, coconut sugar and shiitakes to the pot. Pour the vegetable broth on top and stir the mixture to combine.

Secure the lid and set the pressure release to Sealing. Select the Pressure Cook (manual) setting at High Pressure and set the cook time to 15 minutes.

Once the timer goes off, allow a natural pressure release for 10 minutes and then perform a quick pressure release.

When the pressure on the Instant Pot has been released, open the pot and, using oven mitts, remove the inner pot. With a fine-mesh sieve set over a large bowl, carefully strain the broth and discard the solids. Season the broth with 1 teaspoon salt. Stir the broth and taste it, adding more salt if desired. Select the Cancel setting.

Assemble the Pho: Place the cooked rice noodles in individual bowls. Pour the strained broth over the noodles and add the baked tofu cubes. Top the pho with the scallions, basil, cilantro, lime wedges, bean sprouts and chilis or sriracha.