Add olive oil to a medium skillet over medium heat. Add the ground beef, and spread it out in the pan.
1 tbsp olive oil, 1 pound lean ground beef
Thoroughly brown the ground beef, then remove it to a colander. Allow the ground beef to drain as much oil as possible.
Add the onions to the pan, plus 2 tbsp of butter. Sauté until translucent. Add the garlic and thyme, and sauté until aromatic.
1 medium yellow onion, 1 clove garlic, 2 sprigs thyme, 2 tbsp butter
Add the tomato paste to the skillet.
1 tbsp tomato paste
Add the browned ground beef back to the skillet.
Toss it all together and cook for a few of minutes.
Adds the Worcestershire sauce.
3 tbsp Worcestershire sauce
Add the red wine. Stir it all together, and scrape up any crusty bits from the bottom of the pan (the fond).
7 ounces dry red wine
Add the flour. Toss it all together and cook for a few minutes.
1 tbsp all-purpose flour
Add hot chicken stock.
2 cups chicken stock
Bring to a boil, then reduce the heat to a fast simmer.
Add the Dijon mustard. Simmer for about 30 minutes. The liquid should reduce by about half, and the sauce should be thick and glossy.
1 tsp Dijon mustard