Chicken Salad Sandwiches

2.5 c chicken about 3 chicken breasts (boiled in chicken broth and shredded)
**whenever I boil chicken I always use chicken boullion and I swear it makes them better**
1 c thinnly sliced celery
1 c halfed grapes
2-3 sliced green onion (optional)
2 T parsley
1 c mayo
1 T lemon juice
1 T Vinegar
1 tsp onion powder
1 1/2 tsp mustard (out of fridge)
garlic salt 1/2 tsp
salt and pepper (1/4 tsp)
dill about 1/4 tsp (optional)
12 Croissants to serve on