Methods/steps

Season the ground beef or bison with a little salt and pepper, worcestershire, mustard, onion and egg.  Gently mix it all together but don't over work it or press it really hard.  Go easy on it.

Make 4 patties and put then into a 12 inch pan over medium heat and cook for about 4 minutes per side.  Then remove, put them on plate and tent them with foil.

Pour off the oil from the pan.  Don't wipe as a small coating won't hurt anything and add the mushrooms.  Cook them over medium high heat until the start to brown 3 - 5 minutes.  If using other vegetables then add them after about 3 minutes.  If there are some brown bits left in the pan from the meat and it's starting to burn add a little wine, water or beef broth.  Just enough to scrape it off the pan and usually the mushrooms will add enough liquid for it to loosen by itself.

When the vegetables have cooked a few minutes add the butter or canola oil, stir in the 2 T flour making sure that it's completely coated and cook for about 2 minutes.  Then add the broth and keep stirring for a few minutes until it starts to thicken and the flour is absorbed.

Add the meat back to the pan.  Spoon some sauce on top and reheat the burger.  Add any juices left on the plate too.  If the juices are bright red you can cook the meat a few more minutes in the sauce but if not you're ready to eat.