Crush the garlic cloves and cut into ½ inch pieces.
Trim the mushroom stems to an even length. Toss the mushrooms in a bowl with the oil, salt, garlic, thyme sprigs and pepper.
Lay the mushrooms out on a cast iron pan or baking sheet lined with parchment and roast at 425 F for 20-25 minutes or until lightly brown. Rotate the pan 180 after 15 minutes.
Shallots
Peel the shallot and slice ¼ inch thick. Heat the shallot slices in a dry cast iron skillet until lightly charred (or just saute them quickly). Remove to a bowl and add the vinegar.
Remove the mushrooms from the oven. Discard the thyme sprigs, transfer to a bowl, add the shallots and olive oil and cool.
Double check the seasoning for salt and pepper and adjust until it tastes good to you. Serve warm or room temperature.
Video
Notes
Variations
Try this with a handful of walnuts mixed in, or with a nut or seed oil like pumpkinseed or walnut instead of the olive oil.