Preheat oven to 400 degrees F.
Into a large skillet over medium-high, add oil. When the oil is hot, add the onions and carrot slices. Saute 3 minutes, until softened.
Add the garlic and continue cooking another 1 minute.
To the skillet, add ground beef substitute, salt, and pepper. Cook and stir until nicely browned and cooked through.
Sprinkle flour over the top. Toss to evenly coat.
Stir in tomato paste, chicken-style broth, Worcestershire sauce, rosemary, and thyme.
Cover and reduce heat to low. Simmer 10 minutes, stirring occasionally.
Add the corn and peas, stirring to combine.
Into an 8' x 8" baking dish, spread mixture in an even layer.
Top with mashed potatoes and spread to completely cover the filling.
Bake, uncovered, 25 minutes.