Quick-soak black-eyed peas.

Simmer peas in water until tender, about 20 minutes, then drain.

In a large bowl, whisk together Dijon mustard, minced shallot, minced garlic, and balsamic vinegar.

Slowly whisk in extra-virgin olive oil until the vinaigrette is emulsified.

Stir the warm peas into the vinaigrette.

Chop bacon into small pieces.

Cook the bacon in a skillet over medium heat until crisp.

Transfer the bacon to paper towels to drain and cool.

Quarter tomatoes, discard seeds, and slice into 1/4-inch-thick slices.

Add the bacon and tomatoes to the pea mixture.

Cut scallions and celery crosswise into 1/4-inch-thick slices.

Cut romaine lettuce crosswise into 1/4-inch-wide strips to measure 4 cups.

Trim arugula.

Add scallions, celery, romaine lettuce, arugula, parsley, salt, and pepper to the pea mixture.

Gently toss until well combined.