With all the new chichi hangouts in Beacon these days, nobody would blame you for walking right past BJ’s Restaurant. But there is a reason that this no-frills, no-nonsense soul food joint has occupied the same Main Street storefront for 34 years: It’s the food. Owner Barbara Sims, a retired nurse who takes care of customers with oversized portions of Southern favorites including her legendary fried chicken ($10.75) and all the fixins’ (like collard greens and corn bread), often greets diners with quiet warmth before letting them know what’s ready to go in the kitchen. And a whole new generation of Beacon mommies are forever grateful for the $2 mac ’n cheese-to-go cup. The popular oxtail (“those need to be steamed for hours,” says Sims), served with two vegetables and bread, costs $10.75, “and that’s including the tax,” adds Sims. You can sit and linger at one of the eight mismatched tables, pick up a stray newspaper, try whatever homemade cake Sims has cooked up that day, and watch the flat screen TV — the only concession to modern times in the whole place.