In a pot, add 1 lb of bone-in and skin on chicken leg, 2 cloves of garlic, sliced; 5-6 slices of ginger, 2 pieces of scallion, 1 tbsp of Sichuan peppercorns, 1 tbsp of salt and 1-2 liters of water, or enough to cover the chicken. Put on the lid. Turn the heat to high. Bring it to a boil.
Once it comes to a boil. Turn the heat to low. Simmer for 5 minutes. Depends on the size of your chicken, you might need to adjust the cooking time. 5 minutes later. Turn off the heat. Remove the pot from the stove. Let it sit for 5 more minutes. Take the chicken out. Put it in an ice bath to stop the cooking process.
While waiting, we can make the sauce. In a blender cup, add 2 slices of ginger, 3-4 cloves of garlic, 0.5 tbsp of pure sesame paste, and 1/4 cup of the water that we cooked the chicken in. Blend everything together.
Pour into a sauce bowl along with 3-4 tbsp of soy sauce, 1 tbsp of Chinese black vinegar, 1 tsp of sugar, 1 tsp of Sichuan peppercorns powder. Mix the sauce. Give it a taste to adjust the flavor. It should be saltier than your normal taste. Add the chili oil depends on your preference. I will add 1/4 cup. Give it a final mix and set it aside.
The chicken is cooled completely. Take it out of the bath. Get a sharp cleaver, cut the chicken into 1/2 of an inch thick pieces.
Placed some cucumber on the plate. Put the chicken on top of it. Pour the sauce all over the chicken. Top a little bit of cilantro as garnish. Enjoy!