Use fresh fruits and veggies. Better for your insects, better fort you since they eat all your dinner scraps. Ditch the premade, processed cubes.
I have found that crickets love turnip greens, carrots, apples, sweet potato, oranges, and bell peppers. Baby carrots and leafy greens are easy to keep in the house.
If you want to add a premade dry food, go with Bug Burger, Cricket Crack, or the Repashy gutload. Those are all good products.