1. Preheat oven to 350 degrees. Toss together bread, 1/2 c. Olive oil and 1 tsp salt in a large bowl, spread in an even layer on a baking sheet. Bake in oven until beginning to sizzle, 5 -10 minutes. Sprinkle half of the cheese over bread, and toss well. Bake 10 minutes, stirring once or twice. Sprinkle with remaining cheese, toss well and bake until croutons are golden brown and crisp on the outside, about 5 minutes more. Let cool on baking sheet to room temperature.
2. Using your hands, crush tomatoes in a bowl. Heat 3 T olive oil in a large saucepan over medium-low. Add onion, and cook, stirring often, until very soft, 5-7 minutes. Add garlic, and cook until soft, about 2 minutes. Add crushed tomatoes, cauliflower, water and 1 tsp salt. Bring to a simmer, cover and cook over low heat until cauliflower is very tender, about 15 minutes.turn off heat and stir in creme fraiche.
3. Blend soup with an immersion blender until smooth. Stir in vinegar. Divide soup among bowls, garnish with chives, pepper and 1 T olive oil. Top with Parmesan cheese.