1. Combine wild boar, salt, thyme, pepper, and dried red chili pepper in a large bowl. Mix well and refrigerate for at least 30 minutes or overnight to marinate.

2. Cook diced bacon in a large Dutch oven or pot over medium heat, around 180°C (350°F), until crispy. Remove the bacon and set it aside.

3. Add 2 tablespoons (30g) of butter to the pot. Sauté 2 cloves of garlic and 200g of mushrooms until they are softened and fragrant.

4. Add the marinated wild boar to the pot, stirring to coat with the mushroom mixture. Cook for 5 minutes or until browned on all sides over medium-high heat, around 200°C (400°F).

5. Add 2 tablespoons (30g) of flour to the pot and stir to combine. Cook for 1-2 minutes, then gradually add 250ml (1 cup) of red wine, whisking continuously. Bring the mixture to a boil, then reduce the heat to low, around 150°C (300°F), and simmer for 10 minutes.

6. Add 200g of sliced carrots, 200g of sliced celery root, and 500ml (2 cups) of water to the pot. Stir to combine, then bring the mixture to a boil. Reduce the heat to low and simmer, covered, for 1 ½ hours or until the meat is tender.

7. Stir in the cooked bacon and 2 tablespoons (30g) of soy sauce. Season the stew with salt and pepper to taste.

8. Serve the stew hot, garnished with fresh thyme if desired.