Cheesy Tomato Zucchini Casserole Recipe

Cheesy Tomato Zucchini Casserole Recipe | DIY Joy Projects and Crafts Ideas

Image credits: America's Test Kitchen via Youtube


If you love your veggies, you gotta try this tomato zucchini casserole from America’s Test Kitchen on YouTube! This mouthwatering veggie casserole has tomato, yellow squash, and zucchini, with caramelized onions and topped with Gruyere cheese. I mean – this is the best veggie casserole you’ll ever taste. 


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In this step by step tutorial, America’s Test Kitchen showed how to shingle these veggies into beautiful layers of only goodness. You’ll love it any time of the day and won’t have any leftovers; it’s just that good!


  • 1/4 cup extra-virgin olive oil, divided
  • 3 onions, halved and sliced 1/4″ thick (about 3 cups)
  • salt and ground pepper, to taste
  • 2 garlic cloves, minced
  • 1 lb zucchini, trimmed and sliced 1/4″ thick
  • 1 lb yellow squash, trimmed and sliced 1/4″ thick
  • 1 lb plum tomatoes, cored and sliced 1/4″ thick
  • 1 tsp minced fresh thyme
  • 2 oz Gruyere cheese, shredded (about 1/2 cup)


Step 1

To start, slice the veggies accordingly and set them aside. Next, heat 2 tbsp of olive oil in a large skillet over medium heat. Once heated through, add the sliced onions and season with 1/2 tsp salt. Cook until nice and golden brown. Add the minced garlic into the onions and saute together for 30 seconds. Turn off the heat and set aside. Now, start assembling the casserole. Grease the casserole dish with about 1/2 tsp of olive oil, then add the caramelized onion at the bottom.

Caramelizing the onions for the veggie casserole
Image credits: America’s Test Kitchen via Youtube


Step 2

Now, shingle the zucchini, yellow squash, and tomatoes alternately into four even layers on top of the onions. Once you have four layers, pluck in the remaining veggies to make the casserole nice and evenly packed. Drizzle olive oil on top and sprinkle 1 tsp minced fresh thyme, a bit of salt, and ground black pepper. Cover the casserole with aluminum foil, put it in the preheated oven, and bake for 30 minutes. After this, remove the foil, sprinkle 1/2 cup shredded Gruyere cheese, and continue baking for another 20 to 30 minutes.

Shingling the veggies into even layers
Image credits: America’s Test Kitchen via Youtube

Cheesy Tomato Zucchini Casserole Recipe

Cheesy Tomato Zucchini Casserole Recipe

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