Remove roots and dark green parts of leek, leaving only white and light green parts.
Slice leeks in half lengthwise, and rinse well to remove all soil and sand.
Cut leeks into 1/4” slices.
Remove seeds from pepper and cut into a medium dice.
Heat oil in a large frying pan.
Add leeks, and sauté for 5 minutes.
Add red pepper, and sauté for an additional 5 minutes.
Remove from heat, and add basil, salt, and pepper.
Serve on small naan or pita bread, sweet potato rounds, or crostini.
Top with feta and balsamic vinegar, as desired.