In a small mixing bowl, combine the San-J Asian BBQ Sauce, olive oil, lemon juice, salt, and pepper. Whisk together. Set aside.
Heat the grill to high. Brush the corn lightly with oil and place on the grill grates. Roast, turning occasionally, until charred all over, about 10 minutes. Remove from grill and let cool. When cool enough to handle, cut the kernels from the ears of corn. Place in a large mixing bowl.
Brush the green onions with oil and roast for 2 minutes per side. Remove from grill and let cool. When cool enough to handle, chop, and add to the corn kernels.
Place the poblanos and bell peppers on the grill and roast, turning occasionally, until the skin is fully blackened, about 15 minutes. Remove from grill, place in a bowl and cover. Let sit for 10 minutes. Remove the skin from the peppers by gently rubbing. Cut in half and scrape out the seeds. Chop and add to the corn along with the cucumber, tomato, and arugula.
Pour the dressing over the vegetables and toss to coat. Serve at room temperature or refrigerate, covered, until serving time.