Sweet Potatoes: I usually grab a bag of frozen, cubed sweet potatoes for this recipe. A 10-ounce bag of cubed sweet potatoes (cooked according to the package) should yield about 1 cup of chunks (about 1/2 cup once mashed), which is enough for a double batch of these dog biscuits. Alternately, you can use leftover sweet potatoes, but be sure that they are completely plain (without spices, butter, marshmallows, etc.).
Turkey / Chicken: As discussed in the post, this recipe is an opportunity to use up leftover turkey OR chicken, and we often utilize the bits of unused meat that we have left after making other recipes. Any cooked, chopped turkey or chicken will work for this recipe, but be very careful not to include any bones. Also, don't use too much of the fatty skin, particularly if the skin has spicy seasonings or a lot of salt on it. Once you've finely chopped your leftover meat for this recipe, you can pre-measure it and store it in a labeled, zippered freezer bag in your freezer until you have time to finish making your dog treats.
Baking round "drop" biscuits: To shape these dog treats into round biscuits, drop the batter by level spoonfuls onto parchment-lined baking sheets. (Because these dog biscuits spread very little during baking, you can crowd them together more than typical cookies.) Using the back of a spoon, flatten the dog treats slightly. Bake until lightly golden brown (which depends on the size of biscuits): about 12-14 minutes for tablespoon-sized biscuits, or 11-12 minutes for teaspoon-sized biscuits. Your yield will be about 48 tablespoon-sized biscuits, or about 130 teaspoon-sized biscuits.