Orange Pasta Salad

1 lb. Pasta shells or macaroni, cooked and drained
1 lb. skinless, boneless chicken cooked and cubed
1 1/4 c. seedless grapes, halved
1 large cucumber peeled, cut into chunks
6 green onions, sliced
1 can mandarin oranges
3/4 c. thawed frozen orange juice concentrate
1/3 c. vegetable oil
1/4 c. rice vinegar
1 tsp. salt
1/2 tsp. pepper
2 tbl. oregano
1/2 feta cheese

In Large bowl, combine pasta, chicken, grapes, cucumber, green onions and oranges. Combine in a separate bowl, the rest of the ingredients to make a dressing to pour over the salad. Top with feta cheese.