Add water, salt, sugar, sliced onion, garlic cloves, and juice of 1/2 lemon in a large sauce pan over medium heat. Bring to a simmer and cook 3-5 minutes, until sugar is dissolved. Remove from heat and let the brine cool completely (about 30 minutes).
Meanwhile, cut each chicken tender into 3-4 bite sized pieces (depending on their size).
Add the chicken nuggets and cooled brine to a Ziploc bag or large container. Press out the excess air from the Ziploc bag before sealing (or make sure the chicken is completely submerged in brine in container before covering with lid).
Refrigerate for 8-24 hours. *Important Note: Do not brine chicken for longer than 24 hours.
Using a colander, drain brine from the nuggets, then rinse nuggets with cool water. Use paper towels or a clean kitchen towel to pat chicken completely dry before seasoning.
Oil the grill grates (or perforated grilling pan) to prevent sticking. Preheat the grill to 350ºF.
Mix the paprika parsley, kosher salt, garlic powder, and onion powder together in a small bowl.
Place chicken on a baking sheet or perforated grilling pan, brush with oil and season on both sides.
Using indirect heat, grill the chicken for 5-6 minutes, then flip nuggets over and cook another 5-6 minutes. Check the internal temperature of a couple of grilled nuggets to ensure it is 165ºF before removing them from the grill.
Spicy Cajun - Add ½ teaspoon of cayenne pepper and ½ teaspoon of smoked paprika to the seasoning mix for a bold, spicy kick.
Lemon Herb - Replace paprika with dried thyme and rosemary, and add extra lemon zest to the seasoning for a bright, fresh flavor.
Honey Mustard - Brush the cooked nuggets with a mixture of honey and Dijon mustard right after grilling for a sweet and tangy glaze.
Storing Instructions:
Leftovers will be kept for up to 4 days in the refrigerator. If you are inclined to make yours in bulk, you can always freeze and reheat with little to no change in texture and flavor. Freeze for up to 4 months in a freezer-safe bag, pressed to remove any excess air.
A quick bake in the oven is a good way to reheat without drying out the meat. Lay them on a baking sheet in a single layer and bake until just warmed through. Another brushing of oil can help keep them moist while reheating.