In a small bowl, mix mayonnaise, mentaiko, ketchup, and chili sauce until well combined. Set aside.
Beef Stir-Fry
Heat vegetable oil in a skillet or wok over medium-high heat. Add minced garlic and beef. Cook and stir beef until browned. Season with soy sauce, sugar, and sesame oil. Set aside.
Assemble
In a medium bowl, mix cooked rice with aonori until well combined. Scoop a serving of rice into each bowl. Cover the rice with beef stir-fry.
Blow torch the beef to give smoky flavor and aroma (optional).
Spread the mentaiko sauce evenly on top of the beef. Blow torch the top while move it back and forth until the sauce turns brown and bubble.