What would you put in duck stew?

Duck, presumably

Wabbit

Can’t go wrong with a good roux, carrots, potatoes, onions, season to taste

Make gumbo! Dark roux, mirepoix, okra, crab meat if you can get it, and spicy spices.

Duck pho is also lovely.

If you have a roasting pan (especially one with a rack) don't stew, roast. Trim the excess skin and fat from around the neck, rub inside and out with salt and spices, quarter a lemon and stuff it inside, and prick the skin all over. Importantly, put some chicken stock and/or beer in the pan to make steam and prevent fat from splattering.

When you turn the bird over for the first time add chopped onion, carrots, celery, and potatoes to the liquid at the bottom of the pan. Once the duck is done you've got the whole bird and premade duck broth vegetable soup in the bottom of the roasting pan. Serve with a nice loaf of bread.

After you're done take the carcass, neck, heart, etc. and throw them in a pot to make stock for next time.

Stuart. I always hated that fucking rat.

Chicken. Probably remove the duck. Toss in some goldfish crackers if I'm feeling fancy.

I've never tried to make a stew out of duck before, but if someone asked me to wing it anyway, I'd probably try to use it in a gumbo: Dark roux, Cajun Trinity (celery + onion + bell pepper), jalapeno, garlic, stock, fresh thyme, bay leaf, lots of fresh ground black pepper, spoonful of hot sauce (e.g. Crystal or Tabasco if I can't get that), plus your meat -- served over white rice. For chicken (e.g. chicken thighs), I'd sear it first but I'm not sure on the best treatment for gamey fowl. Personally I might try to blanch it first to try to reduce the gameyness (based on recommendations I've seen about cooking certain kinds of stewed pork -- like pork belly in Chinese dishes), but you'd do better to get advice from someone who's actually cooked with gamey ingredients more than I have if you can.

Adapting a coq au vin recipe might be another idea to try if gumbo doesn't appeal, but again, I've never tried that with duck either.

Grain, but don't call me Stu.

Stew so potatoes, carrots, onion.

If you want to lean into the stronger flavors parsnips or leeks.

I've made stew from wild game before. It always comes out really gamey. I eat game, but I usually stick to the grill with it. The entire stew picks up on the game flavor, which I'm not keen on.

Keep in mind that I have no idea what I'm talking about.
So, the final form of the game meat should be that of small cubes. Boil it separately whole or large chunks in water with a slight pinch of salt and a cup of rice. Once the rice is nice and soft, get the meat, dice it, stir fry it in a tea spoon of olive oil or butter and some sauce of preferred taste, then stew as usual. Add some green stuff or dried green stuff towards the end.

Very important. Do not add that rice to the stew. If you want to, boil some separately and add that second one. The first rice is full of bad stuff and should be thrown away. We only used it to massage the meat.

If you have any kind of pickled vegetables, have some as a side dish.

Good luck.

Too bad an innocent duck had to die for your meal.