1. Peel shrimp; devein, if desired.
2. Bring 8 cups water to a boil in a medium-size Dutch oven; add shrimp, and cook 3 to 5 minutes or just until shrimp turn pink. Drain shrimp, and coarsely chop.
3. Stir together mayonnaise and next 3 ingredients; fold in shrimp and coleslaw mix. Spoon about 3/4 cup shrimp mixture just below center of each tortilla; top with avocado slices and cashews. Roll up tortillas, and cut in half. Serve immediately, or wrap in plastic wrap and chill up to 2 hours.