- Trim any rough ends/bits off of the broccolini stalks. Cut thicker stalks (greater than 1/2-inch) in half lengthwise. Fill a large bowl with ice water, set aside.
- Bring a large pot of salted water to a boil. Add the broccolini, and cook for 2 minutes. Use a slotted spoon to transfer to the ice water to stop the cooking process.
- Meanwhile, heat the sesame oil and 1 Tbsp of the vegetable oil in a large skillet over medium-high heat until shimmering. Add the garlic, and cook until softened and fragrant, about 1 minute. Stir in the chili paste and sugar, and cook for another 30 seconds or so.
- Drain the broccolini, and gently pat (mostly) dry with a paper towel. Add the broccolini to the skillet, and drizzle with the remaining oil and vinegar. Sauté for 1-2 minutes, until tender but still bright green (think vibrant, al dente, not limp). Season with salt and pepper, to taste. Sprinkle with the sesame seeds. Best enjoyed immediately!