Roasted Onion Butter

A deeply flavored roasted onion butter with notes of caramelized garlic, thyme, sage, and black pepper. The onions and garlic are roasted in olive oil until slightly charred and tender, then blended with softened butter to create a highly versatile flavored butter.

bowl of roasted onion butter


Roasted Onion Butter

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butter flavored with roasted onions, caramelized garlic, thyme, sage, and black pepper

yield: approximately 2 cups


  • 2 lbs yellow onions, cut into 1” wedges (see photos)
  • 4 large garlic cloves
  • ¼ cup olive oil
  • 1 small bunch fresh thyme sprigs
  • 1 small bunch fresh sage sprigs
  • kosher salt
  • freshly cracked black pepper
  • 2 sticks (½ lb) salted butter, softened
  • ¼ cup roughly chopped fresh sage


  1. Preheat the oven to 400°F. Add the onions to a 12” cast-iron skillet. Lightly smash the garlic cloves with the flat side of a knife and add them to the onions. Drizzle in the olive oil and toss to coat. Nestle the thyme and sage sprigs between the onions. Season with a good pinch of salt and freshly cracked black pepper.
  2. Roast for 1 hour. Lower the oven temperature to 350°F. Roast for another 30 minutes, or until the onions are tender and slightly charred. Allow to cool at room temperature for about 30 minutes (the onions should still be slightly warm).
  3. Remove the herb sprigs. Add the onions and garlic to a food processor, along with all of the olive oil from the skillet. Process until smooth.
  4. Add the softened butter and chopped sage. Process until combined. Use the butter immediately or store in the fridge for up to a week.

bowl of roasted onion butter

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