Boil the chopped cauliflower in salted water until very tender. Strain out all the water, reserving some, and puree cauliflower in a blender until velvety smooth. You may need to use a little of the cooking liquid to get it to spin, but don’t use too much; you want the puree to be on the thicker side. Season to taste with salt and white pepper.
In a pot large enough to fit all the ingredients, heat the canola or grape-seed oil and sear the ground boar. Once the boar is caramelized, strain off any excess fat. Add butter and garlic to the meat and cook until light brown. Add onion, carrot, celery, and diced fennel, and cook until soft.
Deglaze the pot with rice vinegar and white wine. Scrape up any caramelized bits off the bottom of the pot. Reduce wine and vinegar until almost dry.
Add the cauliflower puree and the cream. Stir to incorporate evenly, adding a little of the cauliflower liquid to loosen if needed. Simmer for 20–30 minutes.
While the Bolognese is simmering, make a pesto by combining the parsley, basil, scallions, and fennel fronds in a food processor bowl. Drizzle ¼ cup of the olive oil over and process on high to start breaking it all up. Add pine nuts, Parmesan, a pinch of salt, and 3 to 4 twists of white pepper, and again process on high speed. Add remaining olive oil and pulse to just combine.
Taste both the Bolognese sauce and the pesto, adjusting the seasoning with salt, white pepper, and lemon juice.
To serve, toss your favorite pasta (cooked and ready to serve) with the Bolognese sauce as desired. Add pesto to your liking and toss just to combine. Sprinkle liberally with grated Parmesan.