In a large pot, heat the vegetable oil over medium heat. Add the minced garlic and sauté for about 30 seconds until fragrant.
Add the sliced mushrooms and carrots to the pot, cooking for 3-4 minutes until they begin to soften.
Pour in the chicken broth and water, bringing the mixture to a boil.
Once boiling, add the instant ramen noodles and cook according to package instructions, usually about 3 minutes.
Stir in the shrimp, spinach, soy sauce, sesame oil, and red pepper flakes (if using). Cook for an additional 2-3 minutes until the shrimp are pink and cooked through.
Season with salt and pepper to taste.
Serve hot, garnished with sliced green onions and a soft-boiled egg if desired.