A very creative take on the theme. Especially loved the sound of slapping the vegetable onto the burger :D
Cooking patties was also very satisfying! Controls were quite interesting and quite hard. But once you get it, it actually makes game many time more fun than playing mouse and click, so props for that. Really liked smashing buttons to get the correct height faster!
For improvements, I would probably suggest adding some kind of level-based approach for introducing mechanics. Where you start with just a few ingredients and grow from there. Even though it was actually fun to play, it was a bit overwhelming at the beginning since I had to do cooking, chopping, and building at the same time.
Would have loved a bit more time per burger since I got stuck on 4.25m burger, because did not manage to chop and cook everything in time. But overall I liked the concept and had fun slapping those vegetables! Really unique game!