I've tried again after reading your comment, and discovered that this was a mistake on my part.
I was trying to use a cooked sausage instead of a raw one, therefore the only "crafting" option was the tomato seed pack. I've just put all ingredients on the crafting bench in hopes that the pizza option would appear, and the raw shrimps made it into a shrimp pizza. So yeah, my mistake for using the cooked sausage, whoops.
Thanks for the help!