Blend mayonnaise and pesto. Cover and refrigerate.
In a medium size bowl add Italian dressing and Nature's Filets, toss to coat. Cover and refrigerate 30 minutes.
Remove Nature's Filets from dressing and place on microwave safe plate. Heat until warmed, cover and set aside.
Toast bread slices. Coat each slice with pesto spread. Place Nature's Filets on toast, sprinkle with red pepper flakes. Top with onion, tomato, and basil leaves.