This is sort of funny... and I say this because, food "likes" and "dislikes" will continue throughout their childhood. LOL
This is just the beginning of it... ! Head's up...
For us, our Pediatrician, does not recommend introducing meats until 12 months old... .and this is per the development of their internal organs. Each Pediatrician is different... but for both my kids, although my Pediatrician was more "conservative" in approach... neither of my kids had any allergies or intolerances/food problems. Ever. Except, my daughter was at about 2 years old, allergic to Kiwi.
Also, your son apparently still has his "gag reflex."
To me... he's had a "lot" of foods for only being 7 months old. ANd be aware, that spinach should NOT be introduced until AFTER 9 moths old. There are enzymes in it which a younger baby cannot tolerate.
It's okay that he is drinking his formula... keep in mind that for the 1st year of life... a baby's PRIMARY source of nutrition is from breastmilk/formula...NOT solids, NOT juices. At this age, food is just to get them "introduced" to it... not having full on "feasts." It is a gradual thing.
A good site for information on food introduction and "good" or "bad" food and WHEN/what age to introduce them, is:
www.babycenter.com
All the best,
Susan