Preheat your oven to 420 degrees Farenheit.
Grab a food process and measure out 3.3 ounces of spinach into it (or do it in two rounds if the spinach will not fit). Gently whizz it up until it's finely shredded (be careful not to blend it).
Now, add in your shredded spinach and all of your spices and 1/4 of wheatbran into a big bowl (save the remaining 1/4 cup of wheatbran for later on in the process).
Then, add in your wet ingredients - your ground beef, parmesan cheese and egg and mix everything together well (I recommend you squish the mixture with your hands) until all of the spinach is well absorbed with the meat and the rest of the ingredients.
Now, please grab two small and shallow bowls, and your food scale. Place the remaining 1/4 cup of wheat bran in one bowl and set aside. With the other bowl, place it on the food scale and tare the scale so it resets to 0.
It's time to form the mixture into meatballs! Grab what you think looks to be 1.5 ounces of meat and place it in the bowl on the food scale. Make sure the meat weighs 1.5 ounces and then shape it into a small, round ball.
Lightly dip the meatball into the wheatbran in your other bowl until the wheatbran is evenly distributed across the surface of the meatball. Set your meatball in a pre-greased muffin tin.
Rinse and repeat until you've formed the whole mixture into meatballs.
Bake the meatballs for 15-18 minutes.
Take out of the oven and let cool for 5-10 minutes. Then serve with a big bowl of my cheesy low-carb pasta or with whatever else you'd like!