Vegetable au Gratin is a versatile side dish that can be made with whatever veggies you like and have on hand. A creamy cheese sauce and breadcrumb topping make this simple dish elegant!
You’ll love it!
It’s not that often that you find a recipe that checks so many boxes, but this is one of those times. Why?
- The kids will love the cheesiness and forget about the vegetables they’re eating.
- It’s beautiful and looks fancy on any table or buffet (even though it’s easy to make).
- It’s easy to make!
- You can use whatever veggies you have and like.
- It can be made ahead of time and rewarmed, or assembled ahead of time and baked whenever you like.
- Use whatever method of cooking the vegetables that you prefer – roast, saute’, steam, etc.
- It’s easily doubled to make a larger side.
Ingredients and Substitutions
First, the vegetables. As mentioned you can combine them as you choose. A list below gives some suggestions, but you can really use whatever you like, what is in season, and what you have.
For the cheesy white sauce you’ll start with butter. We often use salted and unsalted butter interchangably (like in Fried Apples or Banana Bread Bundt Cake) and just adjust the added salt accordingly.
Flour thickens the sauce. In this recipe you’ll use plain all purpose flour.
The fat content of the milk for the sauce is entirely up to you too. We usually keep skim (non fat) and 2% milk on hand and will use one of those, but whole milk or 1% work fine too.
Our cheese of choice is cheddar and our personal favorite is extra sharp cheddar. But again, if you prefer a milder cheddar or a different type altogether – go for it! Just make sure it’s a cheese that melts well.
That finishes up your sauce as long as you’ve added a bit of salt, if needed. Cheese can be quite salty and if you’ve used salted butter your sauce may be salty enough. Just give it a taste!
This post contains affiliate links, which means if you click on an affiliate link and buy something, we may receive a very small commission. It does NOT result in additional charges to you or cost you anything extra. Click here for our full privacy and disclosure policy. As an Amazon associate we earn from qualifying purchases.
The veggies and sauce then get mixed and go into a baking dish.
The final topping is a light layer of breadcrumbs. We keep this variety on hand in our pantry all the time and they’re great. But, if you like making your own breadcrumbs, by all means, use those!
How to make Au Gratin Vegetables
- Start with about a pound and a half (which equals about 3-4 cups) of vegetables which have been cooked. More details on that are below.
- Next you’ll make your cheese sauce by first melting butter in a pan over low heat.
- Whisk the flour into the milk until smooth and then add it to the butter, whisking as you add.
- Turn the heat up to medium low and continue cooking until thickened.
- Stir in the grated cheese until melted. Add salt if needed.
- Now combine the cheese sauce and veggies and add to a 9×9 inch or similar sized baking dish.
- Top with breadcrumbs and bake at 375 degrees for about 30 minutes.
Full Make Ahead Instructions are found below in the recipe card.
About pre-cooking the veggies
For the best Veggie Au Gratin your vegetables will be cooked just to the crisp tender stage because they will get a bit more cooking after the casserole is assembled and baked.
We like to roast our vegetables and that’s done in a 375-400 degree oven on a parchment lined baking sheet. Just toss with a little olive oil and salt, if you like. Cook them until your desired tenderness is reached.
If you prefer to steam or saute’ yours that’s fine too. Just cook them like you normally do.
No matter the method we recommend that you cut the pieces into sizes according to how long it takes to cook that particular veggie. We use this practice with Smoked Vegetables and Roasted Carrots and Green Beans.
For example, carrots take longer to cook than green beans so we cut them into smaller pieces. Squash cooks fairly quickly so it would get cut into larger pieces.
Alternatively, you can add the veggies to the heat in order of how long they take to cook and we use that method with our Vegetable Beef Soup.
You could even use fully cooked vegetables for this dish, like with leftovers or from cans. In that case we recommend only baking the gratin for about 20 minutes and you would want to turn the oven heat up to 400 degrees.
What vegetables are good in your cheesy au Gratin?
The sky’s the limit really, but below are some suggestions to get you started:
- Green Beans
- Yellow Squash
Vegetable Au Gratin
- Melt butter in skillet or sauce pan over low heat.
- Add flour to milk and whisk until smooth.
- Stir flour mixture into butter, whisking to get out any lumps.
- Increase heat to medium low, and cook, stirring constantly until thickened.
- Add cheese and stir until melted, adding salt if needed and remove from heat.
- Combine vegetables and cream sauce and put into a 9×9 inch (or similar size) baking dish. Top with breadcrumbs.
- Bake at 375 for 30 minutes or until bubbling and top is lightly browned.
- Vegetables may be roasted, steamed or boiled.
- An alternate cheese may be used as long as it is a type that melts well.