So a few days ago when Boris was really restless and couldn't find anything to really hold his interest, I spread out the mat and poured some lentils into a bowl. I got some metal measuring cups out and let Boris go wild.
He really enjoyed them again, scooping the lentils from one cup to another, spreading them around, running his fingers through them, stirring them, pouring them, sprinkling them through his fingers, throwing them about. I didn't mind that the lentils went EVERYWHERE because he was so engaged with the activity. It came to an end when he took a scoop full of lentils outside and....started eating them.