Brussels Sprouts - Can you eat that stalk?

Stems from all the brassicas (broccoli, cauliflower, kale, etc.) are edible. Some are tougher than others, but if you peel the stem you should find a more palatable pith. Eat it raw or cooked lightly or as an addition to soups.

Chopping or thinly slicing the stalk across the grain and then steaming them makes an edible vegetable. They're not normally eaten because they're very fibrous. Make the fiber a non-problem and you can eat it. It'll have less sugar than broccoli stalks, but otherwise should be quite similar.