If you want to go the vegetarian option, shiitake mushrooms are good: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6213178/. Interestingly, the mushroom's D content is based upon how much exposure they have to UV.
Shameless plug -- I wrote an article about growing them at home, it's not too hard. We eat a lot of them: https://www.mushroom.guide
Shameless plug -- I wrote an article about growing them at home, it's not too hard. We eat a lot of them: https://www.mushroom.guide