Can we get plant-based/vegan cooking options, please?

@gertie47Ah right I see, I'm with you now. So that needs to be addressed at some point then, I'm surprised that's been missed. I'll not attempt it with a vegan Sim then. But that doesn't help your problem unfortunately.
You could see if there's a meat wall/plant in the Gallery maybe 🤔 as @PipMenace has already mentioned, if you don't have a Sim in the Civil Designer career.

Edit: I've tested this now and find that I can prep a Meat Substitute. It can only be used for certain recipes though.

To other Vegan simmers, please feel free to add your workarounds/headcanon when you play the game. We can make this our official "Vegan Sims 4 Lore" 😉

Until the Sims team gives us official representation, we at least have our magically vivid imaginations! 

Headcanon and cheats to live as a vegan in a game that is unfriendly to vegans... especially now ingredients are more defined with the Home Chef Hustle stuff pack out:

• Turn off 'fresh ingredients' and 'prepped ingredients' when making any recipe. Own an apple tree for "eggs", a cow plant for "milk" and a meat wall for "meat." After collecting from each thing, you can make the recipe using the headcanon that you used those items. (download from gallery if necessary)
  
  
• Cheating aspiration goals is not cheating when you refuse to cheat an animal (even if it is pixels) of their life or quality of life. I complete all possible parts of the milestone, then cheat as 'complete' whatever I deem unethical.
  
  
• Console players, or vanilla PC players, refusing to cheat animals of their life/quality of life, finish aspiration milestones after fulfilling all ethical tasks: press shift-ctrl-c, type 'testingcheats true', type 'aspirations.complete_current_milestone'
  
  
• Mod-using PC players refusing to cheat an animal of their life/quality of life finish an aspiration milestone after fulfilling all ethical tasks using a mod like UI cheats.
  
  
• e.g. of when I will cheat an aspiration milestone: An ethical vegan can only prep 4 of the 6 ingredient options in the Appliance Wiz aspiration. I do the 'music' part & the 'excellent' part, then make 4 recipes & cheat as complete.
  
  
• Another e.g. of cheating an aspiration milestone: For an ethical vegan to complete the Market Magnate aspiration, to make waffles with batter, I turn off fresh ingredients and prepped ingredients & don't make them until I've picked apples & fed a cowplant. 
  
  
• I'd love to hear a workaround for Horse Ranch (I don't own). For Cottage Living, I don't collect eggs/milk/wool if I have a sanctuary for chickens/cows/llamas. I only adopt in Cats And Dogs.
  
  
• When making Ambrosia for the Market Magnate aspiration, collect the death flower and the potion of youth. Then afterwards, either cheat to complete that section of the aspiration or download Ambrosia from the gallery to sell, using the headcanon that you made it with the collected ingredients. I also sold the potion of youth on the stand, though sims will not drink it, they just take it. I suppose if you have Horse Ranch you could collect the death flower and potion of youth, then make a vitality nectar and sell that to a ghost to bring it back to life, then cheat the aspiration as complete. 
  
  
• Cheat Butler/Nanny traits to be vegetarian and lactose intolerant, so they are less likely to make unsuitable dishes autonomously... Ctrl-shft-C .. TestingCheats True .. Cas.fulleditmode ... Edit traits in manage worlds...

I will add more as they come to me....I have also posted this to my twitter (? ...X?...) I am Persephone on there.

A Meal Delivery Service in-game could offer plant-based options too, making it easier for vegan Sims to stick to their diets without always cooking from scratch!

in flagrante delicto is a legal term meaning caught in the act of committing an offense or commonly "caught red handed".  I think you might mean "in the raw".   I suspect this was an autocorrect mistake though.