Step 1

Heat oil in a large skillet over medium-high heat. Sauté the onion until it's soft and lightly browned, for about 3-4 minutes.

Step 2

Add garlic and mushrooms, stir, and sauté until they become soft and golden brown, for about 8-10 minutes.

Step 3

Add the flour and cook over medium heat for 1-2 minutes, stirring frequently.

Step 4

Gradually whisk in the vegetable stock until the mixture is smooth without any lumps.

Step 5

Add the spices (thyme, salt, and pepper) and give it a good stir.

Step 6

Bring the mixture to a boil, then reduce the heat to medium and continue cooking for approximately 5 minutes or until it thickens, making sure to whisk frequently.