Using a food processor or spice/coffee grinder, grind the oats to a fine powder.
Transfer the oat powder to a large bowl and combine with the millet flour, whole wheat flour, salt, onion seed, baking soda and all purpose flour.
In a small bowl, combine the yogurt, water and ghee and mix well.
Add this to flour mixture and mix by hand until you have a soft dough.
Cover and let rest for 15 minutes.
Preheat oven to 425 F.
Spray 2 cookie sheets with non stick spray. (Even if you use parchment or waxed paper still spray the paper with non stick spray. This will ensure the samosas get a nice golden brown color on both sides.)
Now it’s time to put together the samosas.
Take a ball of dough and roll out to a 6-inch circle as thin as possible. The dough is soft, but not sticky so it is very easy to roll thin. Using a pizza cutter or a very sharp knife, cut in half.
Place a few tablespoons of filling on one half and fold over so that you have a point on the top.
Fold over the other side and the bottom, using water to seal the edges.
Place on prepared cookie sheet. Repeat until all of the dough has been used.
Brush the tops with milk and bake for 20 minutes.