One packet of spice or two?

[Sleep404]

I'm cooking for 16 this weekend. We'll be out all day so I decided to make a lamb tagine using a waitrose spicentice spice pack. It's for 650g of lamb but I've got about 1.5kgs. Should I use two packs of the spice and double up all the other ingredients (onions, tin tomatoes, dried apricots, flaked almonds)? I'm worried I might make it too strong.

I would double the spice mix if you are not too sure, and increase the onions and tomatoes in ratio. If I were making it I would also make sure to taste for salt and pepper and then lots of fresh chopped coriander or flat leaf parsley to again to taste. ( not sure if fresh coriander i s authentic but I love it on most things!)