A man rents a room, and pays extra on the condition the landlady prepare his work lunch every day.
So on the first day, she packs him a sandwich on normal sandwich bread, using the last night's leftovers of meatloaf, adding in some fruit and a bottle of soda.
When he comes home, he politely tells her that it wasn't quite enough food for him.
The next day, she makes two sandwiches (turkey this time), and adds a container of salad, some crackers and peanut butter, and a slice of cake.
That night, he told her most apologetically that while the food was delicious, he found himself still hungry, and could she possibly put in a little more tomorrow?
The next day, she uses long slices of sourdough bread to construct a pair of huge sandwiches, and includes crackers and peanut butter, chips and dip, and veggies and ranch dressing, and a whole 2-liter of soda.
That night, he smiles very kindly, and tells her it was almost enough food.
The next day - throwing caution to the wind, and idly wondering if she's feeding his entire workplace - she cuts a loaf of bread in half and stuffs it with pounds of meat and cheese, an entire head of lettuce, tomatoes, onions, other vegetables, sauces: everything!
That night, he fixes her with a dry look and says, "So, I see we're back down to one sandwich?"