Parmesan

Toss Brussels sprouts in butter before adding parmesan for better adherence. The cheese adds nuttiness and saltiness; for more nuttiness, use Parmigiano-Reggiano.

Vinegar

Roasting Brussels sprouts brings out their sweetness, so once they’re done roasting, drizzle balsamic vinegar on top. The vinegar’s tartness will balance out the sweetness.

Bacon

Adding bacon to sprouts will cover sweet, salty, bitter, and umami taste profiles. Wrap sprouts in bacon or just chop and sprinkle raw bacon over the sprouts before roasting.

Brown Sugar

Melt some butter in a pan and add some brown sugar to it, depending on your taste preference. Add steamed Brussels sprouts to the glaze for a deep caramel flavor.

Pepper

If you prefer simplicity, grind fresh black pepper over raw or cooked sprouts just before serving for a slight spice kick. For a milder heat, use pink peppercorns instead.