Prepare the Couscous: In a medium pot, bring 1.5 cups of water to a boil. Add the couscous, stir, and reduce the heat. Cover and let it steam for 10 minutes until tender. Fluff with a fork.

Cook the Mushrooms: While the couscous is cooking, heat olive oil in a large skillet over medium heat. Add the onions and garlic, and sauté until soft and fragrant, about 3 minutes. Add the sliced mushrooms, oregano, thyme, salt, and pepper. Cook until the mushrooms release their moisture and become tender, about 8 minutes.

Combine: Once the couscous is cooked, add it to the skillet with the mushrooms. Stir well to combine, allowing the flavors to meld together.

Finishing Touches: Stir in the fresh parsley and a squeeze of lemon juice (optional). Top with crumbled feta if desired, and serve warm.