Take 1 lb fresh (preferred) or thawed frozen (acceptable substitute) blueberries. Add 1/2 c lemon juice and 1/2 c brown sugar, mix and let sit for a moment. In a separate bowl, mix 1/4 c corn starch and 1/4 c flour. Sprinkle mixture over blueberries, one mixing one spoonful at a time, until they are lightly coated. Use in blueberry pies, cobblers, on waffles, or wherever else you may need a blueberry filling (hint: everywhere). Cook at least 20 minutes at 350 degrees for saucy goodness, though longer time or higher temperature is fine too, depending on your recipe.
So good. seriously. so good.