Heat a large skillet over medium heat, add the oil. Once hot, add diced onion and mushrooms and cook until all of the liquid has evaporated and the mushrooms have started to brown, about 8 minutes.

Remove half of the mushrooms from the skillet and set aside.

Add the garlic and cook for 1 minute. Then add the couscous, vegetable broth, salt and pepper.

Bring it to a boil, cover with a lid, and turn off the heat. Let it rest for 5 minutes.

Open the lid and add the reserved mushrooms back in. Then add the fresh dill and lemon zest. Stir everything together well.