Start the Miso Ramen: In a large Dutch oven or pot, heat the grapeseed oil over medium heat. Add the onion and cook, stirring occasionally, until golden brown around the edges, 8 to 10 minutes. Add the garlic and ginger and cook, stirring constantly, until fragrant, 1 to 2 minutes. Pour in the vegetable stock. Cover with the lid slightly ajar and bring to a boil over medium-high heat, then reduce the heat to medium-low and simmer for 15 to 20 minutes to let the flavours infuse.
Meanwhile, boil the eggs and set aside toppings: Bring a medium saucepan of water to a boil over medium-high heat. Gently lower the eggs into the water. Adjust the heat, if needed, to maintain a gentle boil and cook the eggs for 6 1⁄2 minutes (adjust timing based on your desired doneness). Fill a small bowl with ice water and gently lower the eggs into the bowl to cool. Peel the eggs and set aside other toppings.
Blend and season the soup: Working in batches if needed, transfer the soup to a high-speed blender. Add the miso, sesame seeds, sesame oil, sambal oelek, and rice vinegar. Blend until smooth and creamy, 1 to 2 minutes. Pour the soup back into the pot, cover with the lid, and keep warm over low heat until ready to serve.
Cook the ramen noodles: Bring a large pot of unsalted water to a boil over high heat. Add the noodles and cook according to the package directions. (Be careful not to overcook.) Drain the noodles.
Assemble: Divide the noodles among bowls, then ladle the soup overtop.
Cut the eggs in half lengthwise. Garnish each bowl with 2 egg halves and toppings of choice.
