In a small mixing bowl, add the sesame oil, minced garlic, oyster sauce, sugar and toasted sesame seeds. Mix all the ingredients together with a spoon and let the sauce sit for 10 minutes.
While the sauce is marinating, chop up the mini cucumbers into 1/4" thick pieces. Transfer the chopped cucumbers to a large bowl.
Add the scallions, cilantro and sauce into the bowl with cucumbers and mix everything thoroughly. Garnish with additional sesame seeds and cilantro and serve immediately.