Sausage plait advice please

[123fushia]

Made a sausage plait with vegan sausages and cooked onions, peppers and garlic for Boxing Day. Am trying out a variety of vegan meals for my daughter. Bought ready made puff pastry, rolled it into a large rectangle, scored it into thirds, and cut the side pieces into slanted strips, put the mixture in the middle part and ‘plaited’ the strips over it, and brushed oat milk on top. Oven baked for 40 mins on 200c fan as packet advised.
It looked fab, sausage part and top plaits were great, but lots of the pastry was undercooked and soggy. What did I do wrong and what should I do next time? Advice gratefully received.

I don't know, but can you buy vegan puff pastry?

Was the oven and tray pre heated? The filling at room temperature?

Oven not hot enough? Heat not equally distributed in oven? If so, turn pastry around mid bake.

It’s a good question. Apparently Jus Rol Puff pastry is. Daughter checked to make sure.

Most ready-made puff pastry is vegan; unless you buy a specific all-butter one it's vegetable fat all the way...

Making sure the filling isn't too wet and doesn't include elements that will 'leak' helps, as does using a thin steel tray for cooking on.

Tray wasn’t pre heated but oven was. Recipe on the packet was for small sausage rolls and said to make them, put onto baking tray and chill for at least half an hour. Then put them in the oven. My plait was much larger but did the same.

I have had this issue in the past.

Once it is nearly fully cooked I put it on a wire cake cooking tray and pop it back in the oven it seems to cook the bottom better

To add to my previous post, I wouldn't use baking paper as IME it makes pastry sweaty. Also, for a large plait, start with a hot oven and once the pastry has risen and started to colour, turn the oven down and cook for longer.

Brilliant advice! Thank you.
I will try all of these ideas next time. Thank you so much for your expertise.👍