I haven’t quite figured out the revolving door situation at Kitchen United MIX (formerly The Gallery Food Hall) at 1315 Third St Promenade in Downtown Santa Monica.  Restaurants seem to come and go with alarming rapidity.  But at least two new eateries are giving the location a go.  Recently, I told you about a branch of Santa Monica Brew Works that is settling in.  And it now appears that Duck Donuts will be occupying the front space.  Duck Donuts has locations across America and offers customizable made-to-order donuts with choices for coatings, toppings, and drizzle.