The broccoli went straight in, but he wasn't expecting to have to swallow & gagged on it.
I had to laugh at this: whenever DS gets something new he tries to eat it and if it's new food he can foget to swallow sometimes too so you can see him wondering what to do next... it's not Duplo so it doesn't come out, but it is getting mushy in there... what next?

If he's gagging then wait a week or so and try again. Or keep with the mashed, it's what feels best to you: I've always done what feels right with DS and that worked well. Aside from the time I listened to DH and used the blender; DS wouldn't eat his favourite meal that night and screamed at the blender. Normally we only use it for cakes and he's fine then, just not when his sweet tomato and aubegine pasta is going in LOL.