Brussels sprouts are a cultivar of the same species that includes cabbage, collard greens, broccoli, kale, and kohlrabi; they are cruciferous. They contain good amounts of vitamin A, vitamin C, folic acid and dietary fibre.
Place trimmed Brussels sprouts, olive oil, kosher salt, and pepper in a large resealable plastic bag. Seal tightly, and shake to coat. Pour onto a baking sheet, and place on center oven rack.
Roast in the preheated oven for 30 to 45 minutes, shaking pan every 5 to 7 minutes for even browning. Reduce heat when necessary to prevent burning. Brussels sprouts should be darkest brown, almost black, when done. Adjust seasoning with kosher salt, if necessary. Serve immediately.