Preparation
Preheat your oven to 225°F. Using a paper towel, pat dry your Boneless Flanken.
Prepare your dry spice rub mixture by combining the chili powder, garlic powder, celery salt, and black pepper in a small mixing bowl. Mix well and set aside.
Prepare your barbecue sauce mixture by combining the ketchup, chili sauce, brown sugar, vinegar, Worcestershire sauce, liquid smoke, dried mustard, and crushed garlic in a mixing bowl. Mix well and set aside.
Cook
Heat a large heavy-bottom skillet on medium to high heat. Rub both sides of your Boneless Flanken with olive oil, and then generously and evenly season the entire roast with your dry spice rub. When your skillet is hot, sear both sides of the roast—about five minutes per side.
When finished searing, transfer your Boneless Flanken into a prepared baking pan. Cover the entire roast with your barbecue sauce mixture. Seal tightly with several layers of heavy-duty foil to ensure no moisture escapes during the cooking process. Place your wrapped baking pan in the center of your preheated oven. Allow to slowly cook for about 14 to 16 hours—or overnight.
Plate
Allow your Smoky Barbecued Overnight Flanken to rest for about ten minutes before slicing against the grain. Serve warm with your favorite side dishes!
Bete’avon!