Vegetable Au Gratin

This post may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases. Please read my disclosure.

My Vegetable Au Gratin recipe combines crisp-tender vegetables baked in a creamy, cheesy sauce and topped with golden breadcrumbs and parmesan. It’s simple to make in under an hour and works wonderfully as both a side dish or a hearty vegetarian main. Even the kids love it!

I created this vegetable au gratin recipe because I wanted a dish that’s comforting, cheesy, and packed with fresh, tender veggies. It’s perfect for busy days when I need a quick side or a hearty main course that my whole family will actually eat. If you’re like me and love simple, flavorful veggie dishes, you’ll also want to try my roasted potatoes and broccoli, another easy favorite!

The first time I made this vegetable au gratin, I knew it would be a keeper. The way the veggies melt into the rich, cheesy sauce with that golden, crispy topping is just irresistible. For a festive holiday spread, I highly recommend pairing it with my vegan meatloaf, so YUMMY and a perfect match!

Latest Recipe Video!

🥘 Ingredients

My vegetable gratin recipe comes together with simple, easy-to-find ingredients from your local grocery store. These are some of the key ingredients you’ll need:

Butter: I always start my cheese sauce with butter because fat is essential in creating a good roux, a thickening mixture of flour and fat that gives the sauce body.

All-Purpose Flour: The flour helps thicken the milk mixture so the sauce isn’t runny, giving it the perfect consistency to coat the veggies.

Low-Fat Milk: Milk forms the base of my cheese sauce. I usually go for low-fat milk.

Cheddar Cheese: For this vegetable au gratin, I use cheddar cheese, but I love experimenting with other meltable cheeses.

Vegetables: I often go with broccoli, cauliflower, and carrots because they’re a delicious combination, but any mix of veggies works well. When I add root veggies like carrots or potatoes, I make sure to slice them thin so they cook evenly.

Panko Breadcrumbs: For a golden-brown, crusty topping, I sprinkle panko breadcrumbs on top. When I want a boost in nutrients, I sometimes use whole-grain breadcrumbs.

Parmesan Cheese: A layer of Parmesan cheese on top hardens as it bakes, creating a perfectly crisp, golden-brown crust that’s irresistibly delicious!

Substitutions

Butter: If I’m out of butter, I use olive oil as a substitute, which works just as well.

Milk: I swap in whole milk, reduced-fat milk, or even plant-based milk, which all work great.

Cheese: Gouda, Gruyere, Monterey Jack, Italian blend, or a mix of cheeses all taste amazing. If I want a lighter dish, I simply reduce the cheese by half.

Vegetables: Other great additions are green beans, zucchini, onions, peas, parsnips, or spinach, and frozen veggies make it even easier.

🔪 How To Make

My vegetable au gratin is ready in less than an hour! Let me show you how to make it with step-by-step pictures, you’re going to love this.

Make The Roux: I start by preheating the oven to 340 degrees Fahrenheit. Then, I melt the butter in a medium saucepan over medium-low heat. Once the butter is melted, I sprinkle in the flour and cook it, stirring continuously for about 2 minutes.

Add Milk & Cheese: I gradually add the milk, about 1/4 cup at a time, stirring after each addition to avoid lumps. Once all the milk is added, I let the sauce cook for another 2 minutes to thicken into a tasty bechamel sauce. Then, I add the cheddar cheese, nutmeg, salt, and pepper, stirring for a few more minutes until the cheese is fully melted and the sauce is smooth. Take the cheese sauce off the heat once it’s ready.

Cover Veggies: In a large casserole dish, I arrange the vegetables in an even layer. Then, I pour the creamy cheese sauce over them, stirring to make sure every veggie is well coated.

Top With Breadcrumbs: Next, I sprinkle breadcrumbs and Parmesan cheese evenly over the top of the vegetables for a crispy finish.

Bake Veg Au Gratin:  I bake the dish in the preheated oven for 30 to 35 minutes, until the cheese melts, the top is golden, and the veggies are tender. If the vegetables need more time, I cover the pan with aluminum foil and bake for another 5 minutes or until the veggies are tender.

📖 Variations

My veggie gratin is super easy to customize! Here are a few tasty variations to try:

Make It Gluten-Free: I can easily make this dish gluten-free by swapping the all-purpose flour for a gluten-free flour blend and using gluten-free breadcrumbs for the topping.

Make It Vegan: For a vegan-friendly version, I use a vegan bechamel sauce along with vegan cheddar and parmesan. This keeps it rich and creamy without any dairy.

Root Vegetables Gratin: For a deeper, heartier flavor, I omit the original vegetables and use sliced root veggies instead. Onions, potatoes, parsnips, carrots, sweet potatoes, fennel, or yucca work beautifully.

Potato Courgette And Cheddar Gratin: When I want a zucchini twist, I replace the mixed veggies with sliced zucchini and potatoes. I salt the zucchini first to release excess moisture, then pat it dry before layering it in the dish.

🍽 Serving Suggestions

My au gratin vegetables pair perfectly with a tasty main course or another side dish. Here are a few of my favorites to serve alongside:

Entree: For a complete meal, I’ll serve this dish with a main entree like my vegan meatloaf, or with my vegan hamburger helper!

Side Dish: I love using a warm, delicious piece of bread to soak up any leftover cheesy sauce from the casserole! My vegan dinner rolls are perfect for that, or when I’m craving something extra special, my focaccia always does the trick!

🧊 Storage Directions

Refrigeration: I cover the casserole tightly and store it in the fridge for up to 3-4 days. This keeps it fresh and ready for easy reheating.

Freezing: I let the casserole cool completely, then wrap it tightly with plastic wrap and foil before placing it in the freezer. It can stay frozen for up to 3 months. When I’m ready to enjoy it, I thaw it in the fridge overnight

Reheating: To reheat, I bake it at 350 degrees Fahrenheit (175°C) until warmed through, usually about 15-20 minutes. For a quicker option, I reheat single servings in the microwave, but I prefer the oven for keeping the topping crispy.

❓Recipe FAQs

📋 Recipe Card