This frittata is made on a sheet pan entirely in the oven for a no-fuss, hands-off cooking method. You end up with an ultra-thin frittata that can be eaten like pizza! Fragrant mushrooms and thyme, creamy, sweet butternut squash and tangy goat cheese come together for a killer frittata perfect for fall. I love eating this as a light breakfast or turning it into a sandwich for a heartier meal.
Ingredient highlight
Winter squash! These dense, sweet, creamy root veggies are a great source of carotenoids (a precursor to vitamin A), vitamin C, vitamin B6, magnesium, and potassium. They are a really nourishing food for athletes and runners because they contain electrolytes, are a great source of complex carbohydrates and immune-boosting vitamins.
P.S. Choose squash that feels firm with no soft spots.
Servings 4
Prep Time 10 minutes 
Cook Time 45 minutes Ingredients
- 1 lb butternut squash (or delicata, acorn, etc… or use sweet potatoes), peeled, cut into small ½-inch cubes (about 2 cups)*
- 3-4 cups sliced mushrooms (¼-½-inch thick from about 8-10 oz)
- 2 tbsp olive oil
- 2 tsp dried thyme
- 1 tsp kosher salt, divided
- 4 cups chopped swiss chard, kale, collard greens or spinach
- 12 large eggs
- 1 cup crumbled goats cheese
- Grated parmesan cheese (optional)
- Black pepper
- *Make sure you cut your squash or potato into ½-inch pieces or smaller so they cook through all the way.
- Add meat! ~ Add 4-8 oz raw sausage torn into bite-sized pieces to the skillet with the squash and mushrooms and toss in the oil, etc…
- Make it a frittata sandwich! ~ See leftovers section.
- Note: ~ an over baked frittata can be rubbery and almost spongy, this is why I like to bake them at a low temperature. You’ll know it’s done when it’s just barely cooked all the way through. There will be some carry over cooking as it cools. Always check on your frittata before you think it will be done to gauge how much longer it needs!
Instructions
- Preheat the oven to 450F or 425F convection. Line a baking sheet with parchment paper.
- Add the squash, mushrooms, oil, thyme, and ½ teaspoon salt and use your hands to toss to coat. Spread out into an even layer and bake for 20-25 minutes or until the squash is tender and browning.
- Add the greens and use a spatula to toss everything together so that the greens get lightly coated in the oil, then spread everything out again and bake for 2-3 minutes. Remove from the oven and reduce the oven temperature to 300F. Use a spatula to toss everything together again and spread out to evenly distribute the veggies.
- In a large bowl, whisk together the eggs and remaining ½ teaspoon salt. Pour slowly all over the veggies. Top with goat cheese, a sprinkling of parmesan (if using), and black pepper.
- Bake for 10-20 more minutes or until eggs are just cooked through (see recipe note, times will vary based on oven temps, so just use your judgment).
- Let sit for 5-10 minutes before slicing so that it can cool down and continue to cook through from the residual heat.
- Use a knife to slice it up and a fish spatula to carefully get the slices out of the pan.
Items you can prep ahead (optional)
- Cut 1 lb butternut squash into small ½-inch cubes (about 2 cups)
- Slice 3-4 cups mushrooms
- Chop 4 cups swiss chard, kale, collard greens or spinach
- Roast the veggies/greens ahead or make the whole frittata ahead
Substitutions:
- To make dairy-free, skip the cheese or use a dairy-free cheese alternative.
- Use any cheese in place of goat cheese – ricotta, cheddar, gouda, parmesan, feta, etc…
- As mentioned, any winter squash or potatoes can be subbed for butternut.
- Use any other veggie you like to roast in place of mushrooms (fennel, cabbage, bell pepper).
Storage:
- Store leftovers in an airtight container in the fridge for up to 5 days.
Leftovers + Repurposing:
- Warm up in the microwave until warmed through. Frittatas heat up very quickly, so it’s best to microwave on low.
- Serve on top of butter bread (or avo toast) with a simple side salad for an easy dinner, lunch, or breakfast!
- Make a frittata sandwich! Mash avocado on toasted bread and squeeze some lemon or lime all over. Add 2-3 slices of frittata and top that with your choice of cheese if you have any (a little extra goat cheese spread on the other slice of toast would be yummy). Of course you can use whatever you want for your sandwich add-ons and layering, this is just what I did 🙂
