What is this plant?

craigleejefferyQQTDK1bC

Can anybody tell me what this is? I have recently moved into my house and have seen this plant grow. It has sprouted all over the garden,and has survived the minus temperatures. It does not have any flowers, is quite thick, and one of the plants is about 60cm high. I keep getting mixed returns on various apps.

Hostafan1

opium poppy?

Topbird

Opium Poppy seconded.

Some people regard them as weeds. I tend to leave quite a few to flower and seed - occasionally you get a real stunner of a bloom and they add a bit of height and colour to the border. I wouldn't let them grow everywhere in the garden or let them all go to seed.