Begin by preheating your oven to 400°F (200°C).
In a large frying pan or skillet, heat the olive oil over medium heat. Add the chopped onion and sauté until translucent.
Next, add the ground beef (or turkey) and cook until browned, making sure to drain any excess fat.
Stir in the diced green chilies, tomato soup, dried oregano, salt, and pepper. Mix well and heat through, then set the filling aside.
In a separate bowl, combine the Bisquick mix and milk (or Master Mix and water) to form a dough. Roll out the dough to match the size of your skillet.
Spread the dough evenly over the meat mixture in the skillet.
Place the skillet in the oven and bake for 15-20 minutes, or until the biscuit topping is golden brown. If your skillet has a wooden handle, cover it with aluminum foil to protect it.
Remove the skillet from the oven and let it cool for about 10 minutes.
Carefully place a heatproof platter or plate on top of the skillet, and then, holding both the skillet and the platter, flip them over to transfer the pie onto the platter.
Top with grated cheddar cheese and return to the oven just until the cheese melts.
Slice and serve the pie like a traditional pie, enjoying each savory bite!