Combine 1/2 cup salsa with cornstarch in small bowl. Stir until
smooth. Pour mixture into slow cooker.
Top with pork roast.
Pour remaining 3/4 cup salsa over roast.
Cover and cook on LOW for 6 to 8 hours.
Remove roast; cool 10 to 15 minutes, then shred pork.
Divide shredded meat evenly on each tortilla. Spoon about 2 tablespoons
of salsa mixture from slow cooker on top of meat. Top with cheese
and lettuce. Fold bottom of tortilla over filling, fold in sides
and serve immediately.