Preparation

Step 1 out of 5

Heat the oil over medium heat in a large skillet, preferably one with sides. Add the onion, garlic, carrots and celery and cook until soft, about 7 to 9 minutes, stirring often.

Step 2 out of 5

Add in the mushrooms and cook another 10 minutes or so until mushrooms are browned and reduced. Depending on how large your skillet is, it may take longer or shorter until mushrooms are well browned.

Step 3 out of 5

Add in the Worcestershire sauce, salt, thyme and paprika. Stir together, then add in the tomato paste and stir until dissolved.

Step 4 out of 5

Sprinkle the flour on the vegetable mixture and stir until just combined. Add the in vegetable broth and cook for another few minutes until thickened. Stir in the frozen peas, then taste as needed for salt/pepper as needed.

Step 5 out of 5

Cover with the leftover mashed potatoes, then cover and cook until heated through.