Today’s gourmet street food movement has its charms, but for those who long for a time when simpler, unvarnished street fare ruled the day, look no further than Grandma Mary’s. Every weekend, on an out-of-the-way street corner just outside the Fruitvale district, Marco “Co” Pollard fires up the grill on his modest street cart and starts serving up hot dogs, links, and lemonade. Before long, a line forms, and the scene starts to feel like a neighborhood cookout. Pollard’s signature dish is the “fully loaded” pastrami link: a grilled hot or mild link topped with pastrami, onions and peppers, pickled hot peppers, cheese, mustard, mayo, and barbecue sauce — a gut-busting, gloriously sloppy, and deeply satisfying sandwich. Like any proper under-the-radar enterprise, Grandma Mary’s doesn’t have a phone number or an official website, but you’ll find the truck in its usual spot from around noon to 6:30 p.m. most Saturdays and Sundays, and Pollard now also grills sausages one or two nights a week at Crate Oakland, a popup venue in downtown. But the best way to keep track of Grandma Mary’s is to simply follow Pollard’s Instagram account, @hotdogco.