Sloppy Turkey Sliders

In a large skillet melt the butter over medium heat. Add the onion and sweet pepper. Cook and stir for 5 minutes. Add turkey. Cook until browned, breaking up with a wooden spoon.

Stir in the brown sugar, vinegar, and salt, scraping up any browned bits from the bottom of the skillet. Stir in tomato sauce and mustard until combined. Cook, uncovered, for 2 minutes, stirring occasionally. Stir in beans; heat through. Spoon turkey mixture into buns to serve.