This ooey-gooey French onion beef casserole doubles as a weeknight dinner or a dinner party meal. The incredible flavours, melt-in-your-mouth beef and stringy melty cheese will have everyone asking for seconds.

This recipe for a French onion beef casserole came to me out of nowhere. I was looking at the recipes on our site and started drooling over our French onion soup and happened to be defrosting stewing beef and voila.

As I started cooking a French onion stew morphed into pasta which further changed into a casserole. And let me tell you that it was worth it.

The flavours in this dish are surprising and comforting all at the same time. If you like an easy cheese casserole then this recipe is for you.

Preparing French Onion Beef Casserole

Ingredients

Stewing Beef: Chuck is the most common cut of beef used for stewing. It’s part of the neck, shoulder and upper arm. You want the meat to have some marbling to give the meat that perfect tender softness once stewed.

Onion: Onion is a very common vegetable that is used both raw and cooked in food preparation. It has a sharp flavour raw that often sweetens once cooked. There are many varieties of onions, some that are milder than others. We use the common onion or yellow onion in this recipe.

Bay leaves: Bay leaves are the leaves of the bay laurel tree. Bay leaves are often added to dishes whole and removed after cooking, before serving. When used in their dry form they don’t soften during the cooking process so are not pleasant to eat.

Thyme: This herb has an amazing flavour that goes so well with most meats and veggies. It is part of the mint family and is a small bush, with branches that are covered in small leaves. These leaves are picked and dried to make dried thyme which can also be used in this recipe instead of fresh thyme.

Flour: The flour is just for coating the beef to seal in a bit of the juices. It’s not a necessary ingredient.

Beef stock: The beef stock carries a lot of flavour. Before putting it in the soup have a taste to test out how salty it is. You don’t want to add salt if you don’t need it. If you find the stock salty enough for you, skip the ½ tsp of salt that we call for near the end of the cooking process.

Worcestershire sauce: This sauce is a complex mix of flavours that turn into a deep pungent and deep condiment. It’s made up of ingredients that include soy, anchovy, malt vinegar, chillies, and tamarind, among others.

Red wine vinegar: Red wine vinegar is made by fermenting red wine. It comes from a variety of grapes therefore many types of wine. It is not quite as acidic as white vinegar and brings a subtle flavour and slight sweetness to dishes.

Butter: Butter is churned milk or cream and is high in fat. It is solidified when refrigerated, holds

a semi-soft, spreadable consistency at room temperature, or can be liquefied when heated.

Penne: Penne noodles are short cylindrical noodles that are cut at an angle. I love these noodles for this dish because it holds the sauce and all the flavourful bits inside each noodle ensuring that you get the full flavour in every bite.

How to Make French Onion Beef Casserole

There is little prep work with this dish with a few extra steps before serving.

Step 1: Prep the onions

The only chopping needed is the onions. Start by peeling and dicing the onions.

If you are using an Instant Pot Duo Crisp, turn on the sauté setting. If not, use a large pan to heat up the butter.

Once the butter is melted, add the onions and saute until softened and beginning to brown.

Step 2: Prep the stewing beef

Now get the beef ready. Make sure the cubes of meat are relatively similar in size by cutting larger pieces in half.

Next, coat the meat in flour and the steak spice.

Add the meat to the slow cooker or turn on the slow cooking function on the Instant Pot Duo Crisp.

Step 3: Set it and forget it

Now add all the thyme, bay leaf, salt and pepper, red wine vinegar, Worcestershire sauce and beef stock.

Stir everything to combine. Place the lid on the crockpot and cook on low for 8 hours or on high for 6 hours.

Step 4: Cook the noodles

When there are about 35 minutes left, set a pot of water to boil for the noodles. Once the water is boiling, add the noodles to the pot and cook until they are just under al dente.

TIP: Cook the noodles for 1 minute less than indicated on the package.

Step 5: Thicken the Stew

While the noodles are cooking, make the slurry by combining water or stock and flour in a small bowl or glass measuring cup. Whisk the slurry together until smooth and there are no lumps.

Next, pour the slurry into the crockpot whisking vigorously to prevent lumps from forming. Close the lid once again and cook until the noodles are ready.

Step 6: Make the Casserole

Preheat the oven to 350˚F.

Once the noodles are cooked, strain them and add them to the crock pot.

Stir everything to combine well and move the mixture to a glass baking dish.

Spread the pasta out in an even layer and grate the cheese over the top.

Place in the preheated oven and bake for 20 minutes.

Serving Baked French Onion Beef Casserole

Baked French onion beef casserole is the perfect complete dish. Top the casserole with freshly chopped parsley for added colour and more vitamin C. Serve with a side of buttered fresh baguette slices which are perfect for wiping up the last bits of the delicious sauce.

Frequently Asked Questions

Can you make vegetarian French onion casserole?

Yes! You can easily make this a vegetarian French onion casserole. First, skip the beef and double the amount of onions, or add mushrooms to replace the meat. Then, use vegetable stock instead of beef stock and you’re all set. If you want to add some extra protein add canned white kidney beans or chickpeas to the casserole before baking.

Let us know in the comments if you have any other questions. And if you like this recipe be sure to leave us a five-star rating below.

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