Make the filling: Preheat oven to 375 degrees F (190 degrees C). Heat olive oil in a large skillet over medium heat. Add the 100g of Aftermeats and cook until browned. Drain off any excess water.
​Add vegetables: Add the onion, carrots and celery to the skillet and cook until softened, about 5 minutes.
​Add liquids and seasonings: Stir in the diced tomatoes, vegetable broth, Worcestershire sauce, thyme, salt and pepper. Bring to a boil, then reduce heat to low and simmer for 15 minutes, or until the vegetables are tender.
Make the mashed potatoes: While the filling is simmering, cook the potatoes in a large pot of boiling water until tender, about 15 minutes. Drain the potatoes and return them to the pot. Mash the potatoes with the milk, butter, salt and pepper until smooth.
Assemble the pie: Pour the Aftermeats mixture into a 9x13 inch baking dish. Top with the mashed potatoes, spreading them evenly.
Bake in the preheated oven for 20-25 minutes or until the mashed potatoes are golden brown and bubbly.
Let the Shepherd's Pie cool slightly before serving. Enjoy!