Peel and roughly chop the onion, celery stalk, carrots, leek, and garlic.

Melt the margarine in a large pot over medium-high heat, then brown the chopped vegetables until deeply caramelized.

Stir in the maple syrup and cook until the vegetables are glazed and caramelized.

Add the tomato paste and roast it for about 1 minute until darker and fragrant.

Pour in the red wine and vinegar, then scrape the browned bits from the bottom of the pot.

Add the vegetable broth, soy sauce, cloves, bay leaf, juniper berries, allspice berry, and black peppercorns.

Simmer the marinade for 20 minutes, then let it cool until no longer hot.

Place the soy big steaks in the lidded container and cover them completely with the cooled marinade.

Refrigerate the soy big steaks in the marinade overnight for at least 8 hours.

Remove the soy big steaks from the marinade and press them firmly dry with clean kitchen paper.

Sear the soy big steaks in a hot pot or pan until browned on both sides.

Strain the marinade through a sieve into the cooking pot, removing the whole spices and vegetables.

Optionally blend a portion of the strained vegetables with the sauce, then return the blended sauce to the pot for a thicker gravy.

Return the seared soy big steaks to the sauce and simmer gently on low heat for 60 to 90 minutes until very tender.