What would a shopping list in Toki Pona look like?
1 kili palisa jelo mute (bananas, lit: many yellow stick-fruits)
2 kala pi loje walo (salmon, lit: red-white fish)
3 moku kasi laso supa (salad greens, lit: flat green plants for eating)
4 telo walo (milk, lit: white drink)
5 kili kiwen lili mute (nuts, lit: many small hard fleshy-plant-food)
6 pan supa sike (pita, lit: flat, round grain-product)
It's worth noting that the translations are ambiguous and personal; if I gave this list to a stranger I might end up with pizza crust instead of pita, or nut milk instead of cow milk. If I wanted to explicitly specify nut milk I'd have to say something like "telo walo pi kili kiwen lili" (lit: white drink of small hard fleshy-plant-food). Having said that, even in English people generally wouldn't go into that level of detail on a personal shopping list. When my partner writes "milk" on the shopping list I know they actually mean a "half-gallon of whole milk" based on prior experience.
The toughest part that comes to mind would be particular spices. You would probably need to start borrowing words to distinguish between things like thyme and rosemary ("namako Tin", "namako Loseli")
kili sike loje isn't enough to distinguish cherries from cherry tomatoes, red grapes, cranberries, red currants, red plums or red apples -- every one of which is a perfectly reasonable thing for me to put on a shopping list.
And so you'll note that we have the words tomato, grape, cranberry, currant, plum and apple.
Now, French has a language academy to decree what is proper, and English --
"We don't just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and rifle their pockets for new vocabulary." -- James Davis Nicoll
A language which isn't useful will either change or be abandoned. Natural languages almost always change.