I always save the juice dripped from the rotisserie chicken. It is pretty concentrated and flavorful. We usually buy rotisserie chicken on a weekly basis and I collected this juice in a jar and store in the fridge for up to two weeks or in the freezer for 3 months. I usually skim off the fat that floats to the top and solidifies before I use it to prepare soup base of any kind. If you don't have this, no worries.
Remove the skin and bones from the rotisserie chicken, shredding the meat into bite-sized pieces and set aside
Toast the spices in a dry pan until fragrant and aromatic over medium-low heat, about 3 minutes. Then I put them inside a mesh spice bag
In a large pot, char the onion, cut-side down, and ginger until slightly blackened and fragrant. If using Instant pot, press saute mode and when it says hot, add the onion and ginger and char them until slightly blackened
Add the chicken carcass and any leftover scraps to the pot or inner pot of Instant Pot. Pour about 8 cups of chicken broth or 7 cups of water and 1 cup of the juice drip from rotisserie chicken. and bring the mixture to a boil. Reduce heat and simmer for about 45 minutes to an hour to develop flavor if cooking on the stove
If you are using an instant pot pressure cooker, pressure cook on high pressure for 20 minutes. Then do natural release after that
Strain the broth through a fine mesh strainer or cheesecloth into another large pot. Discard the solids.
Season the soup base:
Return the strained broth to the stove and bring it to a simmer. Add the seasoning ingredients to the soup base and adjust to your preference.
Cook the noodles:
Cook the rice noodles according to the package instructions. Drain and rinse them with cold water to stop the cooking process.
Assembling:
Divide the cooked rice noodles among serving bowls. Top each bowl with shredded rotisserie chicken meat.
Carefully ladle the hot chicken broth over the noodles and chicken in each bowl.
To serve:
Thinly sliced the yellow onion and soak in cold ice water for 5 minutes. This helps to crisp up the onion and also to remove the strong sharp taste of raw onion
Serve the pho with bean sprouts, fresh herbs, lime wedges, thinly sliced onion, and sliced chili peppers on the side. Everyone can customize their bowls to their liking. I like to serve mine with sriracha chili sauce and hoisin sauce