Cottage Pie

I cooked up the base veg - onions, garlic, celery and grated carrot. Added the mince and then tomato and home-made beef stock.
I also added lentils 1) to reduce the amount of meat needed 2) to economise 3) to bulk it out 4) for a better spread of nutrients and 5) for flavour.
Then before I baked it in the oven with the mash I added fresh herbs from the garden. Both boys loved it and it served several meals for the family. Now that's my sort of cooking, simple, budget, nutritious and does multiple meals.
What's your favourite bulk-cook meal?