Bring a small pot of water to a boil, carefully lower the egg into the water, and cook for 6.5 minutes for a soft-boiled yolk.
Remove the egg and place it in an ice bath immediately; once cool, peel and slice in half.
In a large saucepan or Dutch oven, heat the toasted sesame oil over medium-high heat.
Add the ground pork, sea salt, and black pepper, breaking it apart with a wooden spoon until browned and cooked through.
Stir in the minced garlic and grated ginger, sautéing for 1 minute until fragrant.
Pour in the chicken broth, tamari, and sriracha, bringing the liquid to a gentle simmer.
Add the dry brown rice ramen noodles to the pot and cook for 3-4 minutes until tender.
Stir in the baby spinach during the last minute of cooking until just wilted.
Ladle the soup into a bowl and garnish with sliced green onions and the prepared soft-boiled egg.