Heat oil in a large saute pan. Add Garlic, ginger and Jalapeño and cook over low heat until the garlic starts to brown slightly. Add shrimp and saute for two minutes. Remove shrimp from pan and set aside. Add Mushrooms and Bok Choy and cook over medium low heat. Add Noodles to a pot of boiling salted water and cook for 3 minutes. When mushrooms and bok choy are cooked through add chicken broth and soy sauce. Bring to a simmer and add shrimp back to the pan. Divide noodles between 4 bowls. Place 5 shrimp in each bowl and divide the vegetables and broth between the 4 bowls. Garnish with pickled Onions.