Trim brussels sprouts and discard bruised leaves.
Remove the leaves and place in a bowl until you arrive at the heart of each sprout (save brussels sprouts hearts for another dish).
Wash brussels sprouts leaves, drain in a colander, then blot excess water with paper towels.
Tip brussels sprouts leaves into a large bowl then add flour.
Toss until sprouts leaves are completely coated then set aside.
Heat sugar and water in a pan and stir until sugar dissolves.
Add thyme, balsamic vinegar and red pepper flakes and allow liquid to bubble.
Keep stirring until you can smell the scent of the thyme.
Dissolve cornstarch in a tbsp of water then pour into bubbling sauce.
Once sauce begins to thicken, lower heat to a simmer and allow the cornstarch to cook for one minute.
Remove sauce from heat and set aside.
Heat oil in skillet until very hot but not smoking.
Carefully add batches of brussels sprouts leaves, stepping away from the skillet every time you do to avoid the oil when it pops.
Do not overcrowd the skillet, take your time to fry the brussels sprouts leaves.
Once edges of leaves are nice and golden, remove with a slotted spoon and place in a paper towel lined bowl.
Repeat instructions 13-15 placing a layer of paper towels between each batch to soak up the excess oil.
Once you have fried all of the brussels sprouts leaves, remove the oil soaked paper towels.
Pour a couple of large spoonfuls of sauce on top of the fried leaves and toss.
The brussels sprouts leaves should be nicely coated, but not drowned in the sauce.
Add more sauce if needed and serve.