Forgot the yeast in a brioche bread recipe This is the brioche bun recipe I frequnetly use:

250 gr potato puree

3.5 cups flour

1 tsp sugar

0.5 tsp salt

2 tsp instant yeast

1 tbsp olive oil

50 gr butter

1/3 cup milk

1 egg

1 tsp bread improver

First mix the dry ingredients, then add melted butter, egg and potato puree. Then add olive oil and milk. 

I followed the instructions but forgot to add instant yeast. And with the mistake remaining unidentified I waited for the dough to rise. But after two or so hours, all of a sudden I figured I didn't add yeat to the dough. 

Is it possible to corporate it into the dough now? What can be done to save the dough?
I will sometimes add yeast late, for instance when I'm not finding a sourdough culture to be adequate for a decent rise, or on the rare occasion when I'm getting poor performance from a particular batch of yeast. 

I typically dissolve it in a small amount of water (or milk for this recipe), work the mixture into the dough, and add a bit of flour if needed to compensate for the added liquid. 

It works.