3 cheesy baked penne with cauliflower and Recipes

head of cauliflower, cored, cut into 1-inch florets, heirloom tomatoes, butter, divided, sliced green onions, coarse kosher salt, all purpose flour, heavy whipping cream, coarsely grated comte cheese (or half gruyere and half fontina; about 9 oz), divided, parmigiano-reggiano , finely grated parmesan cheese, divided, creme fraiche, whole grain dijon mustard, penne (3 1/2 cups), fresh breadcrumbs (from crustless french bread ground in processor)

milk, unsalted butter, all-purpose flour, nutmeg, freshly grated, penne or 1 lb mostaccioli pasta or 1 lb rigatoni pasta or 1 lb elbow macaroni, frozen peas broccoli cauliflower carrots, provolone cheese, diced, parmigiano-reggiano cheese, freshly grated, separated