Cut all the vegetables into pieces of roughly the same size so they cook evenly. The pieces should be between 1 and 2 cm in width and height—in other words, fairly small. Place all the vegetables in a large pot, add water, Bong veal stock (it’s the best), and a little pepper. Bring to a boil and skim off the foam that forms on top; this will give you a glossier and more attractive red wine sauce as the final result.

Let it all simmer until the liquid has reduced by half. This can take 1–2 hours. The longer it simmers, the more flavorful it becomes, so it’s best to let the sauce simmer for a couple of hours.

Now it’s time to add the red wine. You can use just about any red wine here, but if it’s downright undrinkable, you shouldn’t use it in the sauce either. It’s great to use leftover red wine from a box or bottle, if you have any.

Once again, let the red wine sauce reduce to at least half its original volume. Once it has reduced by half, you can start tasting it. If it now has a rich, concentrated flavor, strain out the vegetables so that you’re left with just the sauce. If you think the flavor is a little “watery,” reduce it some more. Taste it again and again until you think it’s really good.

Keep in mind that there is a lot of salt in the veal stock and in the butter that you’ll be adding shortly, so don’t add any salt until the very end.

Cut the cold butter into cubes of about 2 x 2 cm and add them to the hot sauce a little at a time while whisking vigorously. The sauce should not boil at this point, as adding cold butter thickens it. If the sauce does come to a boil, it will thin out again. It’s no big deal if that happens—just add a little cornstarch dissolved in cold water and bring it to a boil to thicken the sauce. Add it little by little until you reach the desired consistency.

Stir in a little caramel coloring for a dark, glossy color. Add more pepper and salt if needed. A pinch of sugar can also be a nice touch. Feel free to sprinkle some fresh thyme on top just before serving.