Sloppy Joes

They have not simmered long enough. The 20 to 30 minutes on low heat is what reduces the ketchup down onto the beef, so cutting it short leaves the sauce loose. Leave the pan uncovered for that stretch if it still looks thin near the end.

Yes, and it works straightforwardly here. Turkey renders much less fat than lean beef, so add a little oil at the start or the mixture will catch on the pan during the first few minutes.

Yes. The meat mixture reheats well and arguably tastes better the next day once the ketchup, brown sugar and mustard have settled together. Refrigerate it promptly and warm it through gently before filling the buns.

Toast the cut sides of the buns before filling them, and let the mixture finish reducing so it is thick rather than loose. Fill them at the table rather than in advance, since the sauce will soak in within minutes.

Yes, but brown the beef with the onion and pepper in a skillet first as the method describes, then transfer everything with the sauce ingredients to the slow cooker. Skipping the browning leaves the meat pale and the mixture greasy.

Something plain and crisp balances the sweetness of the sauce, so oven fries, coleslaw or a simple green salad all suit it. Pickles on the side are the usual accompaniment.