Rotten pheasant

It was a test. He wanted to see who would eventually break his rule about such a ridiculous thing.

Blackthorne had a preference for red meat and poultry instead of fish, vegetables and rice. The pheasant was a gift from another hunter (Toranaga in the series) to Blackthorne. His cook did not object to preparing the bird, but his household staff were all horrified that he hung it up to age. He ordered that no one touch the bird until he decided to have it cooked.

Later on after the neighbors complained about the rotting meat, it was decided that the gardener would dispose of the bird. He did so and turned himself in to Fujiko. She sent him to be executed and all was well. Except for when Blackthorne had a fit over the incident.

It's supposed to show the clash of cultures. Problem is they overdid it. It was (and still is) common to hang game birds for a while after killing them. When the birds take flight, that sudden burst of adrenaline affects the taste of the meat, in what is already a bird known to be stringy, tough and rather bland-tasting if eaten just after the kill. What tenderizes the meat from hanging is not rotting, it's pH changes in the muscle cells after death that allow naturally occurring proteinase enzymes in cells to become active. These enzymes break down collagen, resulting in more tender meat.

The Australian government actually did a study and ran experiments:

"Pheasants hung for 9 days at 50°F have been found by overseas taste panels to be more acceptable than those hung for 4 days at 59°F or for 18 days at 41°F. The taste panels thought that the birds stored at 59°F were tougher than those held for longer periods at lower temperatures. Pheasants hung at 50°F became more ‘gamy’ in flavour and more tender with length of hanging."

I say they overdid it on the show, because there wouldn't have been the terrible stench and clouds of flies. Rotting -- the tell-tale greening of tissue, and awful smell -- is the result of bacterial waste products, and bacterial growth is caused by exposure to warm temperatures and air. This episode takes place in what looks like late fall or early winter (there's snow on the ground in some scenes). It's not warm enough, nor did the bird hang long enough to rot and draw all those flies. Hanging a pheasant, when done under the right conditions and temps, doesn't allow the bird to rot, just to age.

Blackthorne has an unstated hatred of gardeners.

No one knows what it means but it's provocative.