Adapted from Tip Buzz
Heat a large high wallet skillet or a medium pot over medium heat, add the oil, onions, carrots, red pepper, zucchini, and meat and cook until the vegetables have started to wilt and the meat is mostly browned.
Add the Worcestershire sauce, chicken stock, vegetables, salt and pepper (and other herbs or spices to taste) and allow to cook until thickened then remove from heat.
Preheat the oven to 190°C, then assemble pie in a 9x9 glass baking pan or similar cooking vessel by placing the meat in the bottom of the pan, smoothing out the top and then placing the mashed potatoes on top, evening out the top until flat. Use a fork or other tool to rough the top of the mashed potatoes into your desired pattern then bake in the oven for 25-30 minutes until the potatoes start to brown on the top.