Heat a thick-bottomed pot over medium-high heat (10 out of 14 on my stove).
Add neutral-tasting oil to the bottom and when it's hot, add the tomato paste. Let it brown a bit before adding the rest.
Cut onions, garlic, carrots, and leeks into smaller pieces and add them to the pot.
After 2-3 minutes, turn down to medium heat (7/8 out of 14 on my stove).
Add the alcohol and ignite it. Make sure the extractor fan is off and do not stand too close.
When the flames have died out, add the white wine.
Let it simmer for a couple of minutes and then add water, peppercorns, and bay leaves.
Cover with a lid and let it cook for 30 minutes. If you have more time, you can certainly let it cook longer.
Strain the liquid into a new pot.