Place pizza crust in medium bowl and allow to come to room temperature. Preheat oven to 400 degrees. Drizzle with 1 Tbsp olive oil and turn to coat. Add oregano and garlic powder and continue turning. Coat a cookie sheet in corn meal and press pizza dough into a circle on cookie sheet.
Bake pizza crust at 400 degrees until lightly brown. Poke with fork as it bakes if dough bubbles form. In the meantime, sautee onions in 1 Tbsp olive oil until soft and golden.
Remove crust from oven and drizzle with 1 Tbsp of olive oil. Cover with sauteed onions. Cover with arugula. Drizzle top with 1 Tbsp olive oil and lemon juice. Slice chicken and place on arugula. If chicken is still warm from the grill, it is even better as it slightly wilts the arugula. Crumble bleu cheese over top. Then add freshly ground pepper. Right before serving, drizzle with balsamic vinegar.
As an alternative, drizzle with low fat caesar dressing instead of balsamic vinegar.