Greek Phyllo-Crusted Baked Oat Casserole

Name: Greek Phyllo-Crusted Baked Oat Casserole
Prep time: 20 min
Cook time: 50 min
Total time: 1 h 10 min
Yield: 6 servings
Cuisine: Greek
Ingredients: 1½ cups (240 g) steel-cut oats; 2 cups (480 ml) whole milk; 1 cup (240 ml) water; ⅓ cup (110 g) honey; 1½ tsp (4½ g) ground cinnamon; ½ tsp (3 g) kosher salt; ¾ cup (90 g) walnuts, toasted and coarsely chopped; ½ cup (85 g) raisins (optional); 8 sheets (240 g) phyllo dough sheets, thawed if frozen; 6 tbsp (85 g) unsalted butter, melted; 3 tbsp (50 g) honey, warm; ¼ cup (35 g) shelled pistachios, coarsely chopped (optional)

From the MyKitchenBank Kitchen

A warm, comforting baked oatmeal with the crispy, buttery layers of phyllo dough on top, sweetened with honey and studded with toasted walnuts and fragrant cinnamon. This Greek-inspired casserole is perfect for breakfast or brunch and can be made ahead and reheated.

Prep: 20 min
Cook: 50 min
Wait: 15 min
Total: 1 hr 25 min
Makes: 1 casserole (6 servings)

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Steps

Before you start

Preheat oven to 375°F (190°C)
Toast walnuts in a dry skillet for 3–4 minutes until fragrant, then chop coarsely
Bring milk and water to a boil before adding oats
Remove phyllo from refrigerator 15 minutes before assembling

1
Cook the oat base
- In a medium saucepan, bring 2 cups (480 ml) milk and 1 cup (240 ml) water to a boil over medium-high heat.
- Add 1.5 cups (240 g) steel-cut oats, stirring constantly to prevent clumping.
- Reduce heat to medium-low and simmer, stirring frequently, for 20–25 minutes until the oats are tender and most of the liquid is absorbed.
- The mixture should still be slightly loose, not stiff.
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Ready when: Oats are tender and liquid is mostly absorbed; the mixture still has a slightly pourable consistency
Tip: Stir frequently to ensure even cooking and prevent sticking at the bottom of the pan
2
Combine oats and flavorings
- Remove the saucepan from heat.
- Stir in 1/3 cup (110 g) honey, 1.5 tsp (4.5 g) ground cinnamon, and 1/2 tsp (3 g) kosher salt.
- Fold in 3/4 cup (90 g) toasted, chopped walnuts and 1/2 cup (85 g) raisins if using.
- Let the mixture cool slightly, about 5 minutes, while you prepare the phyllo.
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Ready when: Honey is fully incorporated and mixture smells aromatic with cinnamon; it feels warm but not piping hot to the touch
Tip: Don't skip the cooling step—hot oats will make the phyllo dough soggy before baking
3
Prepare baking dishOven 375°F / 190°C
- Preheat oven to 375°F (190°C).
- Lightly brush a 9×13-inch (23×33 cm) baking dish with some of the 6 tbsp (85 g) melted butter.
- Pour the oat mixture into the dish, spreading it into an even layer with a spatula or the back of a spoon.
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Ready when: Oat mixture is evenly spread in the dish and reaches the corners
Tip: A light butter coating on the dish prevents sticking and adds flavor to the bottom crust
4
Layer phyllo sheets
- Work quickly to keep phyllo from drying out.
- Unroll the 8 phyllo sheets on a clean surface.
- Place one sheet on top of the oat mixture and brush it lightly with melted butter using a pastry brush.
- Repeat with 3 more sheets, buttering each one.
- For the remaining 4 sheets, brush and layer them as well, using all the butter.
- Crumple the top layers slightly for a rustic, golden appearance.
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Ready when: All 8 phyllo sheets are stacked and buttered; the top looks crinkled and irregular
Tip: Work quickly and keep unused phyllo covered with a damp towel to prevent it from drying out and becoming brittle
5
Bake the casseroleOven 375°F / 190°C
- Place the baking dish in the preheated 375°F (190°C) oven.
- Bake for 40–50 minutes until the phyllo top is deep golden brown and crisp, and the oat mixture is bubbling slightly at the edges of the dish.
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Ready when: Phyllo is deep golden brown and crackling sounds come from the crust; oat mixture bubbles at the edges
Tip: If the phyllo browns too quickly before the edges of the casserole bubble, tent it loosely with foil for the last 10 minutes
6
Cool and finish
- Remove the casserole from the oven and let it cool for 10–15 minutes.
- While still warm, drizzle 3 tbsp (50 g) warm honey over the phyllo top.
- Scatter the chopped pistachios (about 1/4 cup / 35 g) over the top if desired.
- The warm honey will soak slightly into the phyllo and bind the nuts.
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Ready when: Casserole is warm but cool enough to touch; honey has begun to pool slightly on the phyllo
Tip: Drizzling honey while the casserole is still warm ensures it flows into cracks and doesn't clump on top

Good to know

Tips

Phyllo dough dries out quickly, so work fast once you unroll it. If it tears, simply patch it with a small piece and butter over it—no one will notice once baked.
For extra crispness, remove foil (if used to prevent over-browning) during the last 5 minutes of baking to allow the phyllo to finish crisping.
This casserole is best served warm, when the phyllo is at its most crispy. It softens a bit as it cools, but still tastes delicious at room temperature.
Make it your own by stirring in 2 tablespoons of orange zest or a pinch of cardamom into the oat mixture for a more distinctly Greek flavor.

Make ahead

You can assemble the casserole (oat mixture in dish, phyllo layered and buttered, not yet baked) up to 4 hours ahead. Cover loosely with plastic wrap and refrigerate. Bake from cold, adding 5–10 minutes to the cooking time. Alternatively, bake the entire casserole, cool completely, cover, and refrigerate for up to 3 days. Reheat, covered with foil, at 325°F (165°C) for 15–20 minutes until warm throughout.

Storage & reheating

Room temperature: up to 4 hours (keep covered loosely). Refrigerator: up to 3 days in an airtight container; reheat covered at 325°F (165°C) for 15–20 minutes. Freezer: up to 1 month, wrapped well in plastic wrap and foil; thaw overnight in the refrigerator and reheat as above.

Substitutions

steel-cut oats → rolled oats (old-fashioned). Use the same amount, but reduce stovetop cooking time to 12–15 minutes. Rolled oats cook faster and will become mushy if overcooked.
walnuts → almonds or hazelnuts. Toast and chop the same way. Either nut pairs beautifully with honey and phyllo and has a similar structure when baked.
whole milk → unsweetened oat milk or almond milk. Use the same amount. The casserole will be slightly less rich but still delicious; it may bake 2–3 minutes faster.
honey → maple syrup. Use the same amount by volume for the oat base and finishing drizzle. Maple syrup creates a slightly earthier flavor and darker color.