Cook the vegetables first: Giving the onion and bell pepper a few minutes to soften first helps build better flavor and keeps the texture from feeling too raw in the finished filling.
Break up the turkey well: As the ground turkey cooks, break it into small crumbles so the sloppy joe mixture has an even texture and is easier to spoon onto buns.
Let the sauce simmer: A short simmer helps the ketchup, mustard, tomato paste, and Worcestershire sauce come together and thicken so the filling is rich and not too runny.
Adjust the sauce to taste: If you like a sweeter sloppy joe sauce, add a little honey or brown sugar. For more tang, add a little extra mustard.
Toast the buns if you can: Toasted buns hold up better and keep the filling from making them soggy too quickly.