Heat the coconut oil in a large pot over medium heat. Add the minced garlic and grated ginger, then cook for one minute until fragrant.
Stir in the Thai red curry paste and cook for another 30 seconds to release its flavor.
Pour in the chicken broth and coconut milk. Bring the mixture to a gentle simmer.
Add the sliced red bell pepper and mushrooms. Simmer for 5 minutes until the vegetables soften slightly.
Add the shrimp and cook for 3 to 4 minutes until they turn pink and opaque.
Remove the pot from heat. Stir in the fish sauce, lime juice, and fresh spinach until the spinach wilts.
Ladle the soup into bowls and top with cilantro and green onions before serving.