In a large pot, heat the coconut oil over medium heat. Once hot, add the sliced ginger, quartered onion, and smashed garlic. Sauté for about 5-7 minutes until the onion is translucent and fragrant.
Add the cinnamon sticks, star anise, cloves, and smashed cardamom pods to the pot. Stir everything together for about 1 minute to release the spices' essential oils. Then, pour in the water and beef broth. Bring the mixture to a boil.
Once boiling, reduce the heat to low and stir in the fish sauce and palm sugar (if using). Let the broth simmer for at least 30 minutes to allow the flavors to meld beautifully.
While the broth is simmering, prepare the flank steak. You can either slice it thinly against the grain or cook it whole. If cooking whole, add it to the broth during the last 10 minutes of simmering. Cook until it reaches your desired doneness (medium-rare is ideal for tenderness).
In a separate pot, prepare the shirataki noodles according to package instructions. Once cooked, drain and rinse them under cold water to remove any odor.
Remove the flank steak from the broth and let it rest for a few minutes before slicing. In serving bowls, place a portion of shirataki noodles, followed by slices of flank steak. Ladle the hot broth over the noodles and beef.
Garnish each bowl with mung bean sprouts, sliced jalapeños, fresh basil leaves, and lime wedges. Serve immediately, allowing everyone to customize their pho to their liking!
