Cook the udon noodles according to the package instructions. Once cooked, drain well and set aside.
In a blender, add the silken tofu, soy sauce, white miso paste, Chinese sesame paste, and mirin. Blend until completely smooth and creamy. Taste the sauce and adjust if needed. Set aside.
Heat a large skillet or pot over medium-high heat and add a drizzle of cooking oil.
Add the white parts of the green onions, minced garlic, and grated ginger. Sauté for about 30 seconds until fragrant.
Add the ground chicken and cook, breaking it apart with a spatula, until browned and fully cooked.
Add the light soy sauce, dark soy sauce, and oyster sauce. Stir everything together and cook for another 1–2 minutes until the chicken is well coated and flavorful. (*If you prefer a thicker chicken topping, mix 1 teaspoon cornstarch with 2 teaspoons water to make a slurry. Stir it into the chicken and cook until the sauce thickens)
To assemble the bowl: Add the cooked udon noodles to a serving bowl. Pour the creamy miso sesame tofu sauce over the noodles and top with the seasoned ground chicken.
Garnish with chopped green onions and sesame seeds. Serve immediately and enjoy!