Beef concentrate (better than bullion brand) made to less than full strength. I used 4 cups of water for this cook. A few pats of unsalted butter, some black pepper and then added a cornstarch slurry. Around 1/4 cup cornstarch hydrated with cold water and then drizzled into the heated soup. Adjust gravy to desired texture. Adjust flavor to desired flavor. I added a teaspoon of sugar as the bullion is sometimes salty. Finished with shiitake mushroom powder. The powder is made from dried shiitakes I have from the Asian grocer. You must remove the stems before putting the mushroom caps in a spice grinder. Grind till it’s powder. Sprinkle the mushroom powder into the gravy which adds a hint of mushroom flavor. Mushrooms have natural MSG which makes them a flavor booster.