Combine all the cottage pie ingredients into medium slow cooker and cook on HIGH for 2.5 hours. Because this stage is cooked before the main assembly stage, I chose high to make cooking faster. However if you have time or want to cook the mince the day before etc you could also do it on low for 5hrs instead.If you are using the one slow cooker for both and washing in between, just be aware an emptier cooker on high will cook hotter/faster so keep an eye on it and adjust times as necessary.Thicken with a little cornflour and water slurry to thicken nicely as you don't want the mince too wet in your boat.Set aside in fridge until needed if not making them straight away.
While the mince is cooking, on stovetop add chopped potatoes and pinch of salt to large pot of water, bring to boil and cook until tender.Drain potatoes and add milk and butter and mash/whip until smooth.Set aside in fridge until needed if not making them straight away.
Fill each boat 2/3 full with cottage pie mince mix. Top with mashed potato. Scatter with grated cheese.
Sit these filled boats in your large slow cooker, in single layer, and cook using tea towel trick
Cooking Times:- If making with cold/pre cooked mince and potato, cook on low for 2hrs or until piping hot throughout. - If making with all ingredients already still hot when assembled, cook on low for 1hr
We served with a side salad
Alternatives:You could swap beef mince for lamb mince and they'd be Shepherd's Pie :) You could also swap large boats for the mini boats and reduce time slightly