Rinse and drain the kidney beans. Place in a bowl and toss with the liquid smoke, BBQ spice rub, salt, and sugar.
Place the kidney beans on a parchment lined cookie sheet and spray with olive oil.
Roast for 30 to 40 minutes in the oven until very crispy. If they are still soft inside, continue to roast in 5-minute increments, until perfectly crispy. They will crisp up even more as they cool.
When they are done, allow to cool, and keep in an airtight container.
Notes
These make an excellent alternative grain-free crouton, bowl topper or snack.