Caramelized Onion Steak Sandwich

Slice onion into very thin slices, separate rings; set aside.

Slice steak, across the grain, into very thin slices, place in a zip lock bag, add cayenne pepper, Worcestershire sauce, oyster sauce and balsamic vinegar to zip lock bag.

Squeeze out air and massage bag to distribute sauces and vinegar through steak; set aside.

Meanwhile, in a large nonstick fry pan, heat oil over medium heat; cook onion, and garlic, stirring occasionally, until medium to dark brown caramelized; 10 to 15 minutes.

Add steak strips with sauces, saute' til medium rare.

Add beef stock or wine and deglaze pan.

Simmer 5 minutes.

Meanwhile, toast bread slices dark brown.

Place 2 slices of toast on warm plate and cover with half the onion and meat mixture.

Repeat on second plate.