When it comes to management challenges, fish fingers and circuses are at opposite extremes: one product is the acme of industrialised food processing, the other the ultimate expression of human creativity and energy. Somehow, private equity has found room for both: last week, Permira agreed to sell Iglo, which makes Birds Eye fish fingers in Europe, after nine years running the frozen foods company, while another buyout group, TPG Capital, led a deal to gain control of Montreal’s Cirque du Soleil.

The coincidence made me wonder at the sheer breadth of private equity-owned businesses, which seems to defy the caricature of buyout kings as asset-stripping short-termists, interested only in targets with an annuity-like stream of revenue. But something else links these two apparently disparate businesses. All great enterprises start like a troupe of inventive and inspired circus performers. But over time most end up churning out the equivalent of pre-cut breaded strips of reconstituted seafood. The big question is: how can entrepreneurial and inventive companies slow their slippery slide to a fish-fingery fate?

I do not mean to disparage the creativity involved in food production. Iglo’s new owner, Nomad Foods, says innovation is one reason it is ready to pay €2.6bn. A few years ago, when I visited Birds Eye’s plant in Lowestoft, on England’s easternmost tip, the man in charge would not let the FT photograph his state of the art potato-waffle-packer, he was justly proud of the scanners that screen out dodgy-coloured peas before processing, and he was trialling new ready-meal combinations. But such incremental innovations are a long way from the original breakthrough of the eccentric Clarence Birdseye, who in the early 20th century, inspired by how Inuit people preserved the fish they caught, invented a way of processing flash-frozen food in bulk and thus launched a billion microwave television suppers.