Chain News: RBI To Buy Firehouse Subs, FAT Brands Picks Up Another Small Chain, Sweetgreen and Portillo’s IPOs

In these days of soaring prices, supply chain issues and ongoing Covid, I often don’t get to the constant chain news. Here’s just a smattering of things I didn’t cover during the past couple weeks:    –Restaurant Brands Intl. the Toronto-based owner of Burger King, Tim Hortons and Popeyes, said it will buy Firehouse Subs, the Jacksonville, Fla., chain, for $1…