"I'm in the mood for something light but really tasty," I told the girl behind the counter at Paulie's (1834 Westheimer, 807-7271). "Oh, then you want the shrimp BLT," she chirped, without a moment's hesitation. How right she was. Paulie's version of this lunch-counter standard ($6.95) starts with a sturdy bun instead of toast, then layers on slices of smoky bacon, a fringe of deep green lettuce and ripe, red Roma tomatoes. Inspiration strikes in the middle, though, in the form of delicately butterflied and grilled jumbo shrimp dressed with a light remoulade sauce. With a side order of parsley-sprinkled potato salad made with red-jacketed new potatoes and briny green and black olives, it was exactly what I had in mind.