In our household of two, we often find you cannot buy in small enough quantities that you don't end up with leftovers that aren't consumed before it's time to trash them. And eating the same meal three days in a row just doesn't cut it, either. I, too, look for the protein on sale, and then try to figure out what I can do with it that will provide three reasonably different meals that don't feel repetitive. For example:
Marinated flank steak, grilled with a few veggies on Sunday. On Monday, more thin slices of steak, in a big skillet full of onions and peppers make for easy fajitas with sour cream, diced tomatoes, and those individual packs of Wholly Guacamole. Third day, leftover steak, peppers, onions, plus melted cheese on hoagie roll.
Or a recent pound or so of fresh shrimp: First day, Vietnamese spring rolls with spicy peanut/hoisin sauce. Second, more shrimp, quickly sauteed, on top of Caesar salads. Third use, sauteed and then tossed with olive oil, butter, garlic, parsley and lemon in angel hair pasta.
We've also lately been buying the Bertolli Premium sauces in microwaveable pouches. There are multiple types. Each one provides two generous servings, and no leftover half a jar in the fridge. Nuke the pouch for 90 seconds on high, and pour it in a bowl on top of cubed up pre-cooked chicken tender meat. The too-hot-to-eat sauce warms the chicken, and then it can go on top of whatever pasta with a little shaved parm for a really quick meal.