Shepherds pie I normally make with Quorn, onions and mushrooms fried together. Tin of chopped tomatoes and about half a pint of stock (top up as you see fit - comes in as extra gravy if you need it) and let it cook, usually add some mixed herbs or fresh if they are in season. I used to add carrot but would be careful to do so now. For mash I am currently enjoying celeriac and swede, but could eat with broccoli/cauliflower as a side veg rather than potatoes. You can pop the mince in the oven with a veg topping and cheese on top, but it's just as easy to plate up, add the cheese and stick it under the grill til the cheese melts. Could alternatively mix cheese through the veg mash as this should also melt the cheese.