Rinse and drain the great northern and black beans.

Dice the tomatoes and bell peppers.

Chop the green onion and cilantro.

In a large bowl, gently combine the beans and tomatoes.

Add the diced red and yellow bell peppers and chopped green onions to the bowl.

Stir lightly to distribute the colors evenly.

In a separate small bowl, combine the salsa, red wine vinegar, cilantro, salt, and pepper.

Whisk the dressing ingredients together thoroughly.

Pour the dressing over the bean and vegetable mixture.

Gently toss the salad to coat the ingredients evenly with the dressing.

Line a large shallow bowl with finely shredded romaine lettuce.

Top the lettuce-lined bowl with the prepared bean salad mixture.

Serve immediately or chill for later.