Season with salt and pepper.
Roast the vegetables, stirring occasionally, until tender and starting to brown, 30 to 35 minutes.
Season with salt and pepper; reserve in the refrigerator.
Spread the mayonnaise mixture on both of the bread halves and arrange watercress on the bottom layer.
Top with the vegetable mixture and the bread tops.
- Daily Values (DVs) are the recommended amounts of nutrients to consume each day.
(-) Information is not currently available for this nutrient.
