Carrots not softening in a casserole

[BlueHotel]

I have a favourite recipe which I call Spanish Stew. It has lardons, onions, chorizo, tinned tomatoes - and carrots. I always used to cut the carrots into quite big chunks but lately they just won't cook, I've had to fish them out and boil them. I tried pre-cooking but then they get mushy.
I've just cooked the dish and cut the carrots much smaller - less than an inch square - and they're still a bit crispy after a couple of hours simmering. Any suggestions?

It might be the tinned tomatoes - are you adding them earlier than you used to? They can stop things softening

older carrots are harder. Spring carrots are softer.

More water? Or give the carrots a quick roast and bung them in towards the end.

I thought it might be the tomatoes, because I don't have the same problem when I do an ordinary beef stew. I always add them right at the beginning though ...

I will definitely try roasting the carrots, great idea as it intensifies the flavour.