Preheat the oven to 450° F.
Put 1 cup of the halved grapes in a heatproof bowl; set the other cup aside for later.
In a medium saucepan, combine the raisins, 3/4 cup of the white wine vinegar, honey, bay leaf, sea salt and crushed red pepper flakes.
Bring to a boil, over high heat; reduce to medium-low and allow mixture to simmer for about 10 minutes, until the mixture has reduced by half.
Pour the hot liquid over the grapes in the heatproof bowl; set aside to allow the liquid to cool completely to room temperature.
Cut 1-1/2 heads of cauliflower into small-ish florets.
Save the other 1/2 head; later, you'll shave it into the salad, to eat raw.
Toss the cauliflower florets with the olive oil, season with plenty of salt and pepper, and put on two parchment-lined baking sheets, making sure there's plenty of breathing room for the florets.
Place in the pre-heated oven and roast for about 25 minutes, stirring once or twice, until the cauliflower is crispy-skinned and quite dark.
Remove from the oven; add 2 to 2-1/2 tablespoons of lemon juice to the cauliflower on the baking sheets and 1/2 of the cheese, distributing among both pans.
Return to the oven and bake for 5 to 7 minutes, until cheese has melted into a mess on your parchment-lined baking sheets.
Remove cauliflower from the oven and immediately stir it with the melted cheese so that the florets are coated and almost no cheese streaks remain on the parchment paper; don't allow the cheese to congeal; set aside.