I remember I tried to get an early version of Midjourney to draw something in ligne claire-style, no matter how I expressed it, it failed miserably at that. It was an early "Yeah, these models are actually pretty overfit" moment for me.
I haven't tried lately, though. I would assume it's better now.
Flux-1-Schnell does pretty decently just by prefixing a prompt describing the subject without style information with “An illustration in ligne claire style.”
Stable Diffusion 3.5 Large does pretty well out of the box (similarly to what I noted for Schnell in another comment, just using “An illustration in ligne claire style…” as the start of the prompt) without any custom fine tuning.
I haven't tried lately, though. I would assume it's better now.