1. Stack half the collard leaves and roll into a cigar shape. Cut crosswise into very thin strips (about 1/16-inch wide). Repeat with remaining half.
2. In a small bowl, combine garlic and salt. Heat oil in a heavy 12-inch skillet over medium heat until it shimmers, then cook garlic, stirring, for about 30 seconds. Add collards with pepper and cook, tossing, until just tender and bright green, 3 to 4 minutes.