Heat the avocado oil in a heavy-bottomed stock pot or Dutch oven over medium heat.
Hit the chicken tenders with some salt and pepper, and place them into the hot oil. Cook them for about 8 minutes, flipping them over with tongs halfway through, until the chicken is fully cooked and has an internal temperature of 165º F. When ready, transfer the tenders onto a paper towel-lined cutting board or plate and set them aside. If there are browned chicken bits stuck to the bottom of the pot, pour in a splash of chicken broth and deglaze the pot; leave the bits in there, they'll add flavor!
If necessary, drizzle a bit more oil into the pot. Stir in the garlic, ginger, and lemongrass, and let simmer for about 15 seconds or until aromatic.
Transfer the chopped bok choy, shiitake mushrooms, carrots, and scallions to the pot and stir to coat. Let them cook for about 5-7 minutes, or until they're tender.
Add the curry paste and mix it in well to lightly coat the veggies.
Pour the chicken broth into the pot and add the turmeric, curry powder, coconut milk, and fish sauce; give everything a good stir. Make sure that the curry paste has completely dissolved and that the coconut milk is well-mixed into the broth.
Bring the soup to a simmer and let it go for about 5 minutes. In the meantime, chop or shred the chicken on a cutting board. (Shred it using two knives.)
Add the egg noodles and the chicken to the soup and simmer until the noodles are fully cooked—about 8 minutes.
Once the noodles are cooked, it's ready to eat. Serve the soup garnished with slices of fresh chile or jalapeños, fresh parsley or cilantro, or crushed toasted peanuts. Add a wedge of lime to spritz some fresh lime juice in there, too!