Preheat your oven to 450°F (232°C) and prepare a baking sheet with parchment paper.

Slice the cabbage into four wedges leaving the core intact, drizzle with olive oil, and season with salt and pepper.

Roast the cabbage wedges cut-side down for 10-12 minutes, then flip and roast for an additional 8-10 minutes until crispy.

In a saucepan, melt butter, add minced onion, Dijon mustard, and minced garlic, cooking until onion is translucent.

Remove the cabbage from the oven, drizzle with the sauce, and garnish with chives or parsley before serving.