In a large skillet, add a tablespoon of canola oil and place over high heat.
Once oil begins to smoke, add steak to the skillet. After 2-3 minutes, flip. Add 2 tablespoons of butter and 1-3 cloves of crushed garlic to the pan and baste until the steak reaches your desired doneness. Remove steak and let it rest for 10 minutes. After 10 minutes, slice steak into small bite sized pieces.
In the same skillet, add the french bread and toast until crisp.
Add in 2 tablespoons of butter and cook onions for 5-10 minutes.
To assemble, add sauce to the bottom of the bread, then add onions, then plenty of steak. Add more sauce to the top of the steak and then close the sandwich with the top bun.