Add 3 cups of water to a saucepan and add in giblets. Bring to a boil then remove fat from the top of the pot and set aside (you will need 4 tablespoons of that giblet broth saved).
You will need to simmer for at least 45-60 minutes to really break them down making them tender. Once tender, drain the giblets, chop very finely and set aside.
Over medium heat in a large skillet, whisk stock, evaporated milk, those 4 tablespoons of giblet broth you saved, and flour until smooth. Continue whisking until it bubbles and the flour taste disappears. This takes about 4 minutes.
Next add in your chopped gizzards, celery, onion, garlic, eggs and 1/2 teaspoon of black pepper and mix it all together.
Get that simmer back then reduce the heat to low heat. Simmer for about 5 minutes, stirring occasionally until it reaches a medium gravy consistency that's pourable but still thickened. Taste, season with salt and pepper as needed the remove from heat, cover and set aside until ready to serve it up.