Toast Ramen noodles and almonds in butter under broiler for 3-4 minutes, stirring often, just until noodles begin to brown. Remove and cool completely. In large salad bowl, toss spinach leaves, oranges, cubed chicken, and onion rings just until mixed. Cover and refrigerate. Place all dressing ingredients in a sealable container and shake until well mixed. To serve, stir noodle/almond mixture into salad mixture. Pour dressing evenly over top, and toss gently. Serve immediately.