In a small bowl, mix cream cheese with chopped herbs and set aside. Slice cucumber very thinly lengthwise using a mandolin or very sharp knife. Spread 3/4 of a tortilla with a layer of the cream cheese mixture (this way the spread won't ooze out when you roll it). With the uncovered portion at the top, arrange a layer of cucumber slices vertically from the bottom edge of the tortilla and then a layer of salmon slices horizontally. Roll tightly. (Use a sushi mat if you own one.) Chill, seam side down, covered with a slightly damp paper towel and plastic wrap. When ready to serve, cut on the bias in 1 1/2-inch slices, discarding uneven ends, and arrange on a serving platter.