Place the wild boar in a large bowl. Season with kosher salt and black pepper. Add the coriander and fennel and toss to coat.
Heat a large heavy pot over medium-low heat. Add the bacon and cook until the fat has rendered and the bacon is golden brown. Remove the bacon and leave the fat in the pot.
Increase the heat to medium-high. Brown the wild boar in batches, about 5 to 10 minutes per batch.
Lower the heat to medium. Add the carrots, celery, onion, and mushrooms. Cook, stirring often, until tender and well cooked down, about 8 minutes. Add the garlic and cook for 2 minutes more.
Stir in the tomato paste. Pour in the white wine and scrape up the browned bits from the bottom of the pot. Cook until the wine has almost fully evaporated.
Add the chicken stock, diced tomatoes with their juices, sage, thyme, rosemary, and reserved bacon. Bring to a slow simmer and cover.
Simmer for 1 1/2 to 2 1/2 hours, or until the wild boar is fork-tender and the sauce has thickened. Remove the lid and reduce gently if needed.
Stir in the heavy cream and bring to a gentle simmer. Adjust the seasoning with salt and black pepper.
Serve over pappardelle, tagliatelle, or soft gnocchi.