Bring 1 inch of salted water to a boil in 2 separate pots fitted with steamer baskets. Add cauliflower to one pot and broccoli to second pot. Cover, and steam until tender when pierced with the tip of a knife, 8 to 10 minutes.
Meanwhile, in a medium skillet, melt butter over medium heat. Cook until butter turns brown, 3 to 4 minutes. Remove from heat, and season with salt.
Remove cooked cauliflower to one platter and broccoli to a second platter. Pour half of the browned butter over the cauliflower. Return pan to heat and add breadcrumbs, cook, stirring frequently, until the breadcrumbs begin to brown. Spoon over broccoli. Serve immediately.