In a small mixing bowl, combine the ingredients for the rub. Rub the mixture on the brisket, then let it marinate for at least 2 hours, up to 18 hours.
In the bottom of the Instant Pot, add the onion, garlic, and chicken broth, and whisk to combine.
Add the marinated brisket. Close the lid and make sure the valve is in the sealing position. Select MANUAL mode (high pressure) for 75 minutes, then once cooked, allow the pressure to release naturally (this will take 15–20 minutes).
Remove the lid, then transfer the brisket to a foil-lined baking sheet.
To make the BBQ sauce, select SAUTE mode. Add the ketchup, honey, apple cider vinegar, Dijon, and brown sugar. Let the BBQ sauce simmer until it thickens, about 10–12 minutes.
Turn the oven on to broil.
Brush the BBQ sauce over the brisket and place in the oven. Broil until the sauce begins to caramelize.
Transfer to a cutting board and slice the brisket against the grain. Serve immediately.
Notes
Recipe Source: Inspired by Amy + JackySTORE the brisket by letting it cool to room temperature first. Place in an airtight container in the refrigerator.With sauce, it will keep for up to 2 days; without sauce, it will last up to 4 days. For longer storage, FREEZE the brisket. Without sauce, it can be stored for up to 2 months; with sauce, it will last up to 3 months.Thaw in the refrigerator overnight if frozen, then REHEAT gently on the stovetop or in the oven at 300 degrees Fahrenheit (150 degrees Celsius) until warmed through.