Begin by washing and preparing your vegetables. Slice the zucchini into half-moons, and thinly slice the onion and mushrooms. Mince the garlic cloves finely.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Wait for about 1 minute until the oil shimmers.

Add the sliced onions to the skillet and sauté for about 3 minutes until they soften and turn translucent.

Introduce the minced garlic and sliced mushrooms to the skillet. Cook for an additional 3 to 4 minutes, stirring frequently.

Once the mushrooms are ready, add the sliced zucchini to the skillet. Season with salt, black pepper, and thyme (if using). Sauté for another 3 to 5 minutes.

Taste test and adjust the seasoning if needed before removing the skillet from heat. Sprinkle with chopped fresh parsley before serving.