My little guy, also seven months, sees me chewing and does this big exaggerated chewing motion with his mouth... very cute!
I've tried to delay solids with all my kids, and each one has started earlier than the one before. My now-three-year-old started solids at 5 1/2 months because I felt like I was torturing her withholding them... but she wasn't all that interested in them and they didn't replace mama's milk at all (no reduction in nursing whatsoever... if anything an increase as she got older) until she was over a year old.
My little guy now started at 5 months (I SO wanted to wait, but again, it seemed like I was just torturing him!)-- he liked it, but didn't really know what he was doing and didn't really consume all that much... maybe a couple teaspoons every couple days. Then all of a sudden he got the hang of it and he opens up for the spoon and loves it. It hasn't slowed his nursing down at all (we do still limit his solids-- he would likely eat more than we offer). We offer little bits of banana, avocado, puffed rice, etc, but it's mostly to keep him busy while we eat because he doesn't actually get it into his mouth except occasionally by accident... in fact, he doesn't really like banana at all, so if he does get it in his mouth he makes a very disgusted face!