In a medium bowl, whisk together the flour, cornstarch, sugar, baking powder, baking soda, and salt. In a small bowl, combine the buttermilk, 3 tablespoons of olive oil, and the beaten egg. Pour the liquid ingredients into the dry ingredients and whisk a few times, so that the items are just combined, but some lumps remain. Allow the batter to rest 30 minutes if you've got the time.
Heat a large heavy-bottomed skillet (cast iron if you've got it) over medium-low heat. Add a couple tablespoons of canola oil and heat until shimmery. Pour 1/2 cup of batter into the center of the pan and immediately scatter a generous tablespoon of chocolate chunks over the pancake, then top that with a small pinch of flaky sea salt, trying not to crush the flakes, if possible. Cook 1-2 minutes, until hollow bubbles appear around the top of the pancake and the edge looks good and crispy. Flip, and cook about 1 minute more, or until the bottom is evenly browned. Repeat this step, one pancake at a time, adding more oil as necessary, until all the batter has been used.
Serve the pancakes with a drizzle of good olive oil instead of butter and syrup (sounds weird but it works!) and some freshly grated orange zest. Yay pancakes!