I think the dish looks nice, I'm sure there are lots of interesting flavors and textures there too.
My suggestion would be to simplify...not simplify in terms of technique or presentation, but more like..what could you remove from the plate to get to the heart of the dish? What do you want the dish to be?
More focused flavors would do you good here. Why do you need potatoes AND pasta? Two starches seem redundant. I would pick one...samphire, cucumber, brocolini, tomato concasse, peas, potatoes...all seems too busy. Focus on one or two flavor/ingredients for garnish. Maybe do garnishes in a few different ways. Think things like charred leeks and green leek top puree. So really, it is still just leeks, but the different ways of using it re-enforces the flavors and makes the dish tighter.
I really like the pasta bit, I think it looks cool and dramatic (but not too flashy or gaudy). I've never seen a sheet of pasta served like that--both filled and open at the same time. So kudos for that.
I actually think your first dish is (the one with carrots and leeks) is the better one. Again, less is more often times. Instead of apple puree...maybe carrot puree?
Please don't take this the wrong way, but your dish looks like a culinary student who is trying way too hard. Focus on a couple complimentary flavor then re-enforce those ideas.
Keep us posted, I love discussions like this. Not too many of them around here to be had. For a pro chef community I feel like there isn't a lot of discussion on menu items and food preparation. Mostly just whining about employees