As restaurants grapple with an uncertain number of diners and limited capacity, even casual spots are offering prepaid, prix-fixe menus. Take modern Korean restaurant Anju, which opens its Dupont Circle patio on Wednesday with four tables and 12 properly distanced seats. (Customers can sit inside only during inclement weather.) Chef/co-owner Danny Lee and his team created a four-course dinner menu for $60, served in two-hour time slots. (A la carte is still offered for takeout and delivery.)