If the leaves are slightly sticky or resiny than i would guess calendula. If it is then it will put off flowers that range in color from yellow to orange. Great edible flower and medicinal too.
While I agree that it could be calendula, it could also be a highly invasive plant called hound's tongue. It, too, has sticky, resinous leaves, and a very similar shape, especially in rosette stage. I'd keep an eye on that lil bugger if I were you, Jules... Hopefully, it is calendula- hound's tongue can be quiet a bear to eradicate.
Curse your sudden but inevitable betrayal! And this tiny ad too!