- Preheat the oven to 375°F (190°C). 
- For the meatless filling: 
- In a large skillet, heat olive oil over medium heat. Add diced onions and garlic, and sauté until softened. Add all remaining meatless filling except for the walnuts. Bring the mixture to a simmer, lower the heat, and cover it to cook for about 15 minutes until all the broth is absorbed. It's ready when lentils are soft. If it runs too dry, add a little water. Add in the walnuts and remove from heat. 
- For the Mashed Potato Topping: 
- Boil the diced potatoes in a large pot of salted water until fork-tender. Drain the potatoes. 
- In a bowl, mash the potatoes with soy milk, vegan butter, salt, and pepper until smooth and creamy. 
- Assemble the pate chinois: 
- Transfer the meatless filling to a large baking dish, spreading it evenly. 
- Then, add the layer of the drained canned corn before spooning on the mashed potatoes to cover the pie completely. Sprinkle top with paprika. 
- Place the baking dish in the oven and bake for 25-30 minutes or until the top is golden brown. For an extra crispy potato topping, broil the top to finish. Watch closely to avoid burning.