01 - In a medium mixing bowl, combine the softened cream cheese, sour cream, lemon juice, chopped dill, salt, and black pepper. Stir with a spatula until completely smooth and well blended.
02 - Spread the diced cucumber on a sheet of paper towels and press gently to absorb excess moisture. Fold the dried cucumber pieces into the cream cheese mixture until evenly distributed.
03 - Lay each flour tortilla flat on a clean work surface. Divide the filling evenly among the four tortillas, spreading it in a thin, even layer all the way to the edges.
04 - Roll each tortilla up tightly into a firm log, keeping the filling compressed as you go. Wrap each roll securely in plastic wrap.
05 - Place the wrapped rolls in the refrigerator and chill for at least 20 minutes so the filling firms up and holds its shape when sliced.
06 - Unwrap each roll and use a sharp chef's knife to slice crosswise into 1/2-inch thick pinwheels, yielding about 6 pieces per roll.
07 - Arrange the pinwheels cut-side up on a serving platter. Garnish with fresh dill sprigs if desired and serve chilled.