Preheat the oven to 400 F. Line a baking sheet with foil and lightly coat it with olive oil. Place the cabbage wedges evenly spaced on the baking sheet.
In a small mixing bowl, combine the olive oil, melted butter, garlic, lemon juice, and red pepper flakes. Brush the mixture onto both sides of the cabbage wedges and season them with salt and pepper.
Roast for 20-25 minutes, until the edges of the cabbage are starting to brown and the cabbage is tender. Cooking time will vary depending on the size of the wedges.
Remove from the oven and serve immediately, sprinkled with crumbled feta and chopped parsley.