EDIT: I had jotted down the time it took to microwave each ingredient, but I thought I had lost my notes. However, I just found them, so here's the information, if anyone is interested. It was all done in a very old 900-watt microwave.
Lemon zest: 2 x 1 min on high
Parsley: 4 x 1 min, then 2 x 30 sec on high
Coriander: 5 x 1 min, then 2 x 30 sec on high
Onions: 2 min, then 6 x 1 min on high
Capers: 1 min on medium, then 5 x 1 min on high
For the "brown butter" powder, I used fat-free powdered milk and, as instructed, spread it on a baking sheet and baked it at 180ºC (350ºF). But rather than baking it for 4 minutes straight until it browned, I baked it in 2 minute instalments, then stirred the powder and put it back in. I did this 3 times, until the powder was acceptably browned (but not burnt).
That is all!