When the going gets tough, the tough slow down. Or at least, that’s Candice Ross’ motto. She’s the founder of the Brooklyn-born and based Stagg Jam, where she makes tasty jams and marmalades in cool flavors including seasoned sorrel, cherry chai, spicy orange with red pepper and fennel, and grapefruit rosemary, a nod to her Louisiana roots. For the past year, Candice has steered the Stagg ship, aiming for ideals that would make her grandad proud (she named the company after…