Heat 2 or 3 inches water in a medium frying pan until it boils then salt it and add the cauliflower. Cook 3 minutes, then remove from water with tongs or spider to a colander. Cool under cold running water. Trim asparagus of tough ends and add to salted water, cook 3 minutes, remove and cool in the same manner as the cauliflower. In a second skillet, while cauliflower and asparagus work, saute shallots and mushrooms together in 2 tablespoons of extra-virgin olive oil over medium high heat until tender, 8 to 10 minutes. Season with salt and pepper and add red wine vinegar to the pan and cook it out, 1 minute. Remove from heat.
Preheat broiler to high and a grill pan or large nonstick skillet to medium high. Drizzle sausage casing with extra-virgin olive oil and prick skin in a few places with the tines of a fork. Grill kielbasa on hot grill pan or in large nonstick skillet 6 to 8 minutes until casing is crisp. Remove sausage and cut in 2-inch chunks on a bias.
While sausage cooks, pile veggies on a platter and add cornichons and chopped pears coated with 2 teaspoons lemon juice. Broil bacon on slotted pan until crisp. Drain, cool and chop. Make the fondue: combine cheeses in a bowl with flour. Rub the inside of a small pot with smashed garlic then discard. Add wine and remaining 2 teaspoons lemon juice and bring up to a bubble over medium heat. Reduce the heat to simmer and add cheese in handfuls. Stir constantly, melting the cheese in batches. Stir in a figure-eight pattern with wooden spoon. Transfer the fondue to fondue pot and top with chopped bacon and smoked nuts.
* If you like, score the tops of a few of the larger mushrooms with a paring knife. It will dress up the serving platter when mushrooms are cooked.