This recipe is great over rice or noodles of your choosing, or just served alongside yummy vegetables.
In a large skillet, over medium-high heat, put in 2 Tbsp of the oil. Within 1 minute, add the beef and saute for about 8-10 minutes. When nicely browned, remove beef from skillet and set aside in a bowl.
To skillet add the 2 Tbsp oil and onion. Saute 5 minutes.
Add garlic, thyme and ketchup (or 1 tbsp tomato paste), cooking until fragrant.
Stir in broth, mustard and Worcestershire and simmer.
While that is simmering, scoop out some hot broth into a cup and whisk in the cornstarch until smooth.
Add cornstarch mixture back to skillet and simmer until reduced and thickened, about 10 minutes. Remove from heat, stir in the beef, and serve.