• Prep the broccoli

  Steam or microwave the broccoli until just tender (about 3–4 minutes). Drain well and add to a medium baking dish.
• Make the cream cheese base

  Heat the cream cheese and milk in pot on the stove top, whisk until the smooth and warm.

  alternatively you can do this in a microwave, heat the milk and cheese for 30 second bursts, whisking after each burst.
• Add the cheddar

  Stir 1 cup of the grated cheddar into the warm mixture until melted.

  (The mixture will be pourable — it thickens in the oven.)

Optional Extra Thickening

• Mix together the small measure of milk and with the corn starch/corn flour, to make a thickening slurry. Add this to the warmed milk and cheese mixture before pouring it over the broccoli.
• Combine

  Pour the cheese mixture over the broccoli and gently stir to coat.
• Make the topping

  Mix breadcrumbs + melted butter + remaining ½ cup cheddar, then sprinkle evenly over the casserole.
• Bake

  Bake at 375°F (190°C) for 20–25 minutes, or until the top is golden and the edges are bubbling.
• Serve

  Allow to cool slightly — the sauce thickens as it rests.