In a medium pan over medium-high heat, add ½ teaspoon sesame oil. Add the pork belly and cook until slightly golden brown. Transfer to a plate lined with paper towels and set aside.
In a medium bowl, add 1 cup drinking water (cold or room temperature). Set aside.
For the poached egg, in a medium pan, add 2-inch of water. Bring to a simmer. Add vinegar. The water should be about 190˚F (88˚C). Crack each egg into a small bowl or measuring cup. Slowly pour the eggs into the water, leaving space in between them. Cook for 4½ minutes, without touching. Carefully transfer the eggs with a slotted spoon to the prepared bowl with the water in it. Set aside.
Meanwhile, in a medium pot over high heat, add the water and dashi packets. Bring to a boil and reduce to medium-low heat. Cook for another 5 minutes. Discard the packets. Reduce to medium-low heat. Add the pork belly.
Place the miso paste in a large heatproof bowl. Add ¾ cup hot dashi. Whisk until the miso has dissolved. Return the miso broth back to dashi. Add the tofu and heat until just warmed through.
To assembly, place the rice into two serving bowls. Scoop pork, tofu and soup over rice. Top with poached eggs. Sprinkle green onions over. Serve immediately with chili garlic sauce.