Clean the cremini mushrooms and cut them into thick wedges. Slice the onion into thin half-moons, and crush and finely chop the garlic cloves.

In a heavy-bottomed pot, heat the olive oil and half of the butter (approx. 15 g). Add the sliced onion, a pinch of salt, and sauté and caramelize over medium heat for 10-12 minutes until golden brown and sweet.

Add the chopped garlic and fresh thyme, then sauté for another 1-2 minutes until fragrant.