Step 1

Prepare a medium-high grill fire.  Grill the bell peppers, turning occasionally, until the skin chars all over, 15 to 20 min.  Or roast the peppers in a 500°F oven until blackened all around. Put the charred peppers in a heatproof bowl, cover with plastic wrap, and let sit until cool enough to handle about 30 minutes.

Step 2

Meanwhile, in a medium bowl, combine the balsamic vinegar, olive oil, the chopped thyme & parsley, salt, and about 5 grinds of pepper.  Mix well.

Step 3

Remove the pepper skins and seeds.  Cut the peppers into thin strips.  Add the peppers to the vinegar mixture and let them marinate for at least 1 hour and up to 3 days.  Allow the pepper strips to return to room temperature before serving.