Set Masterbuilt Gravity Series to 450°F.
Grill your bell peppers on all sides, making sure the skin is blistered and blackened.
Once blackened, add your bell pepper to a GLAD bag and allow them to steam for 30 minutes.
After 30 minutes, remove peppers from the bag and use a dry paper towel to rub the burnt skin off the peppers.
Slice peppers in 1-inch strips.
Add peppers to a small bowl with thyme, crushed garlic, salt, pepper, bay leaf, olive oil and red wine vinegar and allow to marinate for 1 hour, or up to 48 hours in the fridge.
Season flank steak with salt and pepper and grill until internal temperature reaches 130°F.
Allow to rest fully and slice thinly across the grain.
Match up 1 slice of steak with one slice of roasted pepper and roll into a spiral using a toothpick to hold in place.
Mix Greek yogurt with chopped thyme, black pepper, lemon juice and French onion mix.
On your serving plate, smear the yogurt on the plate and arrange the steak and peppers rolls onto the plate. Drizzle the plate with the residual marinade and steak drippings.