You know how when you cook if you cook a certain number of things to get an achievement you'll get a bonus recipe too? I'd love to see that applied to making bubbles, gas and possibly fruit too. So that once you've made a certain number you'll get new recipes for them. Because there don't seem to be a lot of gas and bubble recipes at the moment when compared to fruit, spices and cooking. Perhaps they'll need other things to make them, like spices to colour them or something. And these finished products might then be useful in new recipes. Maybe some even have interesting effects like the herbs.
Bubble ideas: Soft, squishy, microscopic, large, rainbow, different colours, shriveled, dehydrated, gooey, slimy, sharp.
Gas: Again other colours, light, blinding (as in very bright), silent, odorous, invisible, hiccuping.
Fruit: Watermelon, kiwifruit, how about some fried fruit things like raisins and sultanas? pears. The made up ones are always great too.