I have found a few things that Ivy loves doing, and is often happy to do on her own for quite a while.
1. Gardening, in the loosest sense of the word. She has a little trowel set and will spend ages just moving soil between pots/dumping it on the deck. And watering, she needs me to fill her watering can every now and then. So, the combination of these two things makes it look like a few bags of compost exploded all over our deck. But who cares?! She's happy, and I get to cook dinner in peace (I am finally realising that losing my cooking mojo is because I never get to do it undisturbed). (this picture from two weekends ago when we planted seeds)
2. Rice play. Some rice, a few containers, a spoon or measuring cup all on a tray, and she spends a long, long time transferring it from one to the other in all the different ways possible. She concentrates so hard and must be learning a lot and loves it. Plenty ends up on the floor too, but if it's not intentional it doesn't count as mess ;)
3. Playdoh and a play knife. Forget rolling pin and all those exciting shaped plastic cutters. Ivy just needs a blunt knife and she cannot be torn away from it (not even for cake, seriously). Also, a great moment earlier when she brought us a piece of playdoh and announced "A playdoh chickpea!" and yes, this piece of playdoh really did look like a chickpea! Do I have the most hippy toddler ever?! (This picture from today, after cutting and squashing the chickpea before we could get a decent photo)