1. Begin by making this variation of my "15 Minute Gravy":
Saute' the onion and peppers in a little oil, over medium / high heat until they're soft. Add the Beef Broth, mustard, paste, and blacken. Bring this to a boil, then turn down to simmer for about 10 minutes while you slice the meat.
2. When you've sliced the meat you'll be eating tonight, it' time to thicken the gravy. Make a slurry out of the cornstarch and a little water. Add about 1/2 of this mixture into the pot, while stirring, or it'll clump up. You've got to bring this back to a boil before the cornstarch will thicken. If you'd like your gravy a little thicker at this point, you can add more slurry. And if you don't feel that the gravy has enough flavor at this point, you can add in a few dashes of Maggi.
3. When you've got the gravy thick enough, add the meat, stir it around for a minute OR two, just enough to heat it up. If you leave it in the gravy too long, it will continue to cook, and end up real tough.
4. I served this with baby peas, and Baked, Smashed Potatoes. The Gravy ended up going well on top of the potatoes also.