01 -
Heat the oven to 425 degrees F. Scrub and dry the potatoes, prick each one several times with a fork, rub with olive oil, and sprinkle with kosher salt. Bake directly on a sheet pan for 50-60 minutes, until the skins are crisp and the centers are tender.
02 -
Steam the broccoli florets for 3-4 minutes, until bright green and just tender. Chop any large pieces and set aside.
03 -
Melt the butter in a medium saucepan over medium heat. Whisk in the flour and cook for 1 minute, stirring constantly, until smooth and lightly foamy.
04 -
Slowly whisk in the milk. Cook for 4-6 minutes, whisking often, until the sauce thickens enough to coat a spoon.
05 -
Reduce the heat to low. Stir in Dijon mustard, garlic powder, black pepper, and cheddar cheese a handful at a time until smooth. Do not let the sauce boil after the cheese is added.
06 -
Fold the steamed broccoli into the cheese sauce. Split the hot potatoes, fluff the insides with a fork, and spoon the broccoli cheese sauce over the top. Garnish with green onions and serve right away.