The mutual admiration between Houston-based OXY and Berkshire Hathaway could well be a case study—if not a master class—in high-risk decisions with multi-billion-dollar bets that make groovy gravy.

Reese Energy Consulting today is following the latest from Warren Buffet’s Berkshire Hathaway, which has acquired Houston-based Oxy’s chemical unit for $9.7 billion. The deal marks the largest for BH in three years and most likely the last with Buffett, now 95, front and center before he steps down as CEO in January. The relationship between the two companies, specifically starting in 2019, has been fascinating to follow.

That was the year Oxy CEO Vicki Hollub, three years into her role and the first woman to lead a major American oil company, found a golden fleece for sale in the Permian bearing the name Anadarko Petroleum. But Oxy needed a financial boost to outbid Chevron in what would ultimately become a $55 billion deal. Hollub traveled to Neb., to meet with Buffet and make the purchase happen. Sure enough, Berkshire Hathaway came through snapping up $10 billion of preferred shares in Oxy stock. In the years since, Berkshire continued to buy Oxy stock, ultimately becoming its largest shareholder.

Since Oxy’s acquisition of Anadarko and most recently CrownRock, the company has been on a crusade to reduce its debt load. With the divestiture of OxyChem, Occidental expects to pay down another $6.5 billion and focus on its oil and gas businesses. Berkshire Hathaway will integrate OxyChem with its other chemical business. A win-win to make more groovy gravy.