Begin by warming the beer (do not exceed 100℉).
In the bowl of a stand up mixer fitted with the dough hook combine the yeast, brown sugar, warm water and warmed beer. Stir and let sit for 5-10 minutes.
Once the yeast begins to foam up, in a separate bowl mix the flour with the salt.
Add to the yeast & beer mixture and mix until the resulting dough separates from the sides of the mixing bowl and forms a ball.
Prepare a clean, lightly floured surface and place the (should be slightly sticky) dough on top.
Knead (to your heart's desire:) or for approximately 3 minutes, adding flour if needed.
Shape the dough into a ball. Divide it into two. Continue dividing the dough into two until you end up with 16 small pieces.
Shape them into small balls and flatten them into palm size rounds by pressing between your palms or laying them onto the working surface and pressing down with the knuckles of your fist.
Arrange the flat rounds onto two quarter size baking sheets (8 per sheet) and brush them with olive oil so that they do not dry out on the surface. Cover well and let sit in a warm place for at least 40 minutes. Once they dough has risen about 1/3 over the original size and is very soft to the touch you can begin grilling the flatbread.
Use medium heat on your grill or heat up a stove top cast iron grill pan over medium heat.
Grill each side for about 2 minutes. Lightly brush each flatbread with olive oil once done and place in a basket lined with a cotton towel. Cover to keep warm.
If making the caramelized onions, begin by slicing the onion very thin. (Do this while waiting for the flatbread to rise.) Over medium heat in a small pan mix it with the olive oil and the brown sugar and let cook until it is soft and begins to caramelize. Transfer to a serving bowl and keep covered until needed to avoid drying out.