Sauce base from America's Test Kitchen

1 small onion, roughly, chopped
1 small carrot, peeled and roughly chopped
250g mushrooms, halved
2 cloves garlic, peeled
1 tablespoon vegetable oil
250g minced beef
1 tablespoon tomato paste
500mls red wine
1 litre beef broth
4 sprigs fresh thyme
2 bay leaves
2 teaspoons black peppercorns
2 packages unflavored powdered gelatin (5 teaspoons)
Process onion, carrot, mushrooms, and garlic in food processor into 1/8-inch pieces, 10 to 12 one-second pulses, scraping down sides of bowl as needed.
Heat oil in Dutch oven over medium-high heat until simmering; add beef and tomato paste and cook, stirring frequently, until beef is well browned, 8 to 10 minutes.
Add vegetable mixture and cook, stirring occasionally, until any released moisture has evaporated, about 8 minutes.
Add wine and bring to simmer, scraping bottom of pan with wooden spoon to loosen browned bits.
Add beef broth, thyme, bay leaves, and peppercorns; bring to boil.
Reduce heat and gently boil, occasionally scraping bottom and sides of pot, skimming fat from surface, until reduced to 2 cups, 20 to 25 minutes.
Strain mixture through fine-mesh strainer set over small saucepan, pressing on solids with rubber spatula to extra as much liquid as possible (you should have about 1 cup stock).
Sprinkle gelatin over stock and stir to dissolve.
Place saucepan over medium-high heat and bring stock to boil. Gently boil, stirring occasionally, until reduced to 1/2 cup, 5 to 7 minutes.
Remove from heat and cover to keep warm. (Leftovers can be frozen for up to a month.)