Preheat oven to 350 degrees F. Line a large baking sheet with parchment
In a large bowl, combine oats, cornmeal and crushed stock cubes.
Add 1/2 cup warm water and stir to moisten. Let stand 10 minutes.
Add the beaten egg, yogurt and shredded cheddar. Stir until well blended.
Stir in flour. Add only as much water to make a rollable dough. I had to use 3/4 cup, but conditions may be such that you would use less (high humidity being one).
Roll out dough on a lightly floured surface to 1/4-inch thickness. Using dog bone cookie cutter or a 2.5-inch diameter glass, cut biscuits. Place on prepared sheets.
Gather up scraps, roll and repeat until all dough is used.
Bake at 350 degrees F for 30-35 minutes. Turn off oven, leaving biscuits in oven to cool completely (this dehydrates them for better storage.
Store in a covered container.
Yield varies by how big a shape is cut. I used a "medium" bone-shaped biscuit cutter and got about 36 biscuits.