Step 1

Trim fat from meat. If necessary, cut meat to fit into a 3-1/2- or 4-quart slow cooker. Sprinkle Greek seasoning evenly over meat; rub in with your fingers. Place onion in cooker. Top with meat and sprinkle with lemon juice.

Step 2

Cover and cook on low-heat setting for 8 to 10 hours or on high-heat setting for 4 to 5 hours.

Step 3

Meanwhile, in a small bowl combine mayonnaise, mustard, and garlic. Cover and chill until needed.

Step 4

Remove meat and onion from cooker. Using two forks, pull meat apart into shreds. If necessary, skim fat from cooking liquid. Return meat and onion to liquid in cooker; stir to moisten.

Step 5

For wraps, spread one side of each tortilla with about 1 tablespoon of the mayonnaise mixture. Using a slotted spoon, spoon a scant 1/2 cup meat mixture onto each tortilla. Top each with 1/4 cup spinach, 3 tablespoons cucumber, 1 tablespoon tomato, and about 1 tablespoon cheese. Roll up tortillas.