Heat oil over medium heat. Add diced onions and minced garlic. Season with salt and pepper and saute until tender, about 5-7 minutes.
Add in the 2 cartons of broth, the grated ginger. Use the back of your knife to pound the lemon grass, just to bruise it to release the flavor. Add it to the broth. Bring to a boil.
Add in the sliced chicken and reduce heat to a simmer. Cook until chicken is cooked through (no longer pink).
Add in the sliced thai chile(s), ground coriander, the fish sauce, coconut aminos, the lime juice, tomatoes, and mushrooms. Continue to simmer until tomatoes are tender and the mushrooms are cooked through, about 4 more minutes.
Add the shrimp and cook 3-5 more minutes, or until shrimp is cooked through.
Stir in the cilantro.
Serve and enjoy!