Tidy 1/2 run off broccoli stalks; make a selection the tricky outer layer with a vegetable peeler. Lower the broccoli lengthwise so the florets linked to the lengthy stalks are 1 to 2 inches huge. Raise 1 run of water to a boil in a Dutch oven fitted with a steamer basket. Steam the broccoli till relaxed, 5 to 7 minutes.
In the period in-between, jog flour and 1/4 cup milk in a little bowl till gentle. Warmth the absolute most reasonable 3/4 cup milk in a saucepan over medium-low heat till steaming. Whisk in the flour mixture; cook, whisking, till thickened, 2 to 4 minutes. Engage away from the warmth; add cheese, salt, pepper and nutmeg (if the spend of). Drizzle over the broccoli. Serve heat.