Place the cubed chicken in a food processor and, using the puree setting, grind the chicken into a paste. Add in the ground sage, sea salt, garlic powder, onion powder, and black pepper. Mix again until all the seasonings have been well incorporated into the ground chicken.
Place a generous amount of cornstarch on a plate and begin dropping small batches of 1/2 Tbsp fulls of the chicken mixture onto the cornstarch. Begin by working each ball of chicken meat around in the cornstarch so it is easier to handle. Then gently work each one out, flattening them into a chicken nugget-sized patty. About 1 inch by 2 inch around and 1/8 inch thick. You want them to be roughly uniform so they cook evenly. I use the palm of my one hand to hold them and my fingertips of my other hand to shape them.
In a medium-sized mixing bowl, combine the sourdough "discard", egg, honey, yellow mustard, garlic powder, onion powder, smoked paprika, chicken bouillon, salt, and pepper.
In a heavy-bottom pan or Dutch Oven, heat the oil to 300-325 degrees Fahrenheit. Do a test run with the oil and cook a few at first to see if the temperatures need adjusting. A very important step is to check the oil temperature between each batch to make sure the oil stays at a consistent temperature. If the temperature is too low, allow time for it to reheat back up to 325 degrees, or if it's too hot. Let it cool down to avoid burning the nuggets. The recommended internal temperature for chicken nuggets is 165 degrees Fahrenheit.
Ideally, you want them to cook 2-3 minutes on each side, flipping them in between. Once they have cooked through and are crispy, place them on a cooling rack to allow any extra oil to drip off.
Serve immediately with your favorite dipping sauce.
Store in the refrigerator in an air-tight container for up to 3-5 days and reheat in the oven at 350 degrees for 10-15 minutes or until they are hot and crispy.