Step 1 / 5
Blanch
well-salted water, 2 minutes, drained HARD
broccoli to bright green and barely tender, drained and pressed dry in a towel — two minutes and no more, because it cooks again in the oven; and the drying is load-bearing: broccoli is a sponge, and wet florets bleed water into the sauce until the casserole swims