Imagine being invited to Sunday brunch at the home of your most elegant friend. She makes a handful of dishes—a strata, a plate of sausage, some homemade scones—and sets them out on the sideboard. She makes you feel welcome. You serve yourself. You linger over drinks. It hardly seems right to call it a buffet. That's what Sunday brunch is like at Nathalie Johnson's place, the Signature Café in Prospect Park. The former policy wonk and her husband bought the neighborhood bistro four years ago. They've built a reputation for using seasonal, fresh, and local ingredients in dishes that skirt the line between comfort and elegance. Oh, and, just as you would with a friend, you need to call Nathalie ahead of time to make plans for brunch: Sunday mornings are strictly by reservation only, so she knows just how much to cook.