In a medium bowl, combine the pork, sesame oil, soy sauce, cornstarch, sugar, and half the garlic; let sit for 15 minutes.
Heat a wok, or a skillet, over high heat. Add the 1 Tbsp. oil and coat the pan. Add the leeks and cook, stirring and tossing constantly, until fragrant, about 1 minute. Transfer leeks to a plate and set aside.
Return wok to heat and add remaining oil. Add the pork mixture and remaining garlic and cook, stirring and tossing constantly, until the pork is browned, about 2 minutes.
Add the reserved leeks to the wok and cook, stirring and tossing often, until just tender, about 1 minute. Serve with rice. Enjoy!