1. In a large bowl, combine mayonnaise, milk, white sugar, lime juice, salt, red pepper and black pepper. Whisk until well mixed.
2. Add cabbage coleslaw mix and pineapple to bowl. Mix gently until well tossed. Reserve in refrigerator or a cool place.
Patties:
1. In a small bowl, combine allspice, thyme, nutmeg, cinnamon, salt, brown sugar and black pepper. Stir well.
2. Place ground chicken in a large bowl. Pour spice mixture onto ground chicken.
3. Add grated onion, garlic and lime juice.
4. Mix well with your hands.
5. Divide into 6 equal portions and form into 6 patties.
Buns:
1. Combine softened butter with scallions. Mix well.
2. Spread scallion butter on the insides of the split brioche buns.
Assembly:
1. Preheat gas grill on medium. Lightly oil grill with olive oil.
2. Place split brioche buns on outer edge of grill rack. Grill each side until light char marks appear, about 1 minute per side.
3. Place chicken patties on grill. Grill for 5 minutes, and then flip over. Grill until patties are cooked through, about 4 to 5 more minutes.
4. Slice each avocado into 6 thin slices.
5. Place chicken burgers on bottom brioche buns. Top each burger with pineapple coleslaw. Add 3 slices of avocado to each, and cover with top bun. Serve immediately with a glass of chilled Sutter Home Gewurztraminer.