Using a 4-quart Dutch oven (or large stock pot), add vegetable oil and place over medium-high heat.
Once hot, add sliced onions and sauté, stirring often, for 1 minute.
Add the garlic, ginger and red curry paste; stir until well combined. Continue sauteing, stirring often, for 1 more minute.
Add the chicken broth, coconut milk, peanut butter and soy sauce; stir until well combined. (Note: Use a spatula or whisk to help break up the peanut butter mixture. This will help it melt better as the broth heats.)
Taste the broth – this is a good time to add more red curry paste if it is not spicy enough!
Once the broth begins to boil, add chicken breast and mushrooms.
Cover pot and reduce heat to medium-low. Simmer for 15 minutes, or until chicken breast is full cooked.
Transfer the chicken to a cutting board and shred using 2 forks; set shredded chicken aside.
Increase heat to medium-high and bring broth to a boil.
Once boiling, add the bell pepper and ramen noodles. Boil according to package instructions, or until noodles are tender (~2-3 minutes).
Remove pot from heat and add shredded chicken (from above) and lime juice; stir until well combined.
Taste the broth – if it is too spicy, add 1-2 tsp of granulated sugar to offset the heat.
Before serving, garnish with lime wedges and chopped cilantro or green onions.
