Boil the spaghetti noodles in boiling water.
Make a shallow cut on the mentaiko and scrape out the roe.
Heat perilla oil in a pan and sauté minced garlic.
Add the mentaiko roe and lightly sauté over low heat.
Add the cooked noodles to the pan and toss quickly.
Season with soy sauce and pepper.
Serve in a bowl and garnish with green onion and sesame seeds.