Boil enough salt water to cook 2 lbs of potatoes, Dice the potatoes before hand to quicken the cook time. Once cooked drain most of the liquid (leave about 1/2 a cup in the pot). Mash the potatoes, adding milk and butter as needed. Season with salt and pepper.
In a small pot pour the Guinness, let it simmer on Medium until it's reduced by half.
Coat a non-stick pan in oil and sautee the garlic and shallots, add the ground beef and sausage. Cook thought and drain.
Line a pie tin with the crust, set aside.
Once everything is cooked your ready to assemble. Pour the beef/sausage mix into the pie crust, then add the carrot, peas and corn (you can use other veggies, this is just what my family likes best). Then pour the Guinness sauce in and top with the mashed potatoes (I usually add some instant potato mix to this to make more if needed). Cover with foil and bake at 350 for 1hour, removing the covering at the half way mark.