A Denver omelette is a diner order for one: ham, green pepper, onion and cheddar folded into eggs, made to order and eaten immediately. This casserole keeps everything people love about that combination and bakes it in a single dish for eight, so the cook eats at the same time as everyone else. The peppers and onion are softened first so they taste sweet rather than raw, the ham is folded through generously, and the eggs bake up tender and sliceable.
It lives in our Breakfast collection with the other feed-a-crowd bakes like our Easy Sausage Breakfast Casserole, and it plays the same role on holiday mornings and slow weekends: assemble it, slide it into the oven, and make coffee while breakfast handles itself. It can also be assembled the night before, which makes it the easiest possible answer to overnight guests.
Egg bakes have one failure mode — rubbery, weeping eggs — and it comes from kindness: cooking them too long, just to be safe. This casserole comes out of the oven while the centre is just set with the faintest wobble, and a short rest finishes it gently. Dice the vegetables small and even so they cook at the same rate as the eggs, and let the dish rest before you cut it; clean squares are the reward.
Soften the vegetables first — it changes everything
Raw peppers and onion stirred straight into eggs release water as they bake and never lose their sharp bite, so the finished casserole tastes unfinished and a little watery. Five minutes in a skillet sweetens the onion, takes the raw edge off the pepper, and drives off the surface moisture that would otherwise thin the eggs. It is the same reason a good diner griddles its omelette filling before the eggs arrive. Let the mixture cool for a few minutes before it meets the eggs so it does not start cooking them in the bowl.
Make it the night before, bake it in the morning
This is one of the few egg dishes that genuinely improves with an overnight assembly: the ham seasons the eggs, the vegetables settle, and the morning work shrinks to heating an oven. Assemble everything in the dish, cover it tightly, and refrigerate for up to 12 hours. In the morning, let it stand on the counter while the oven heats and add about 5 minutes to the bake, since it starts cold. Do not freeze the unbaked casserole — raw eggs and vegetables both suffer for it.
Ingredients
- 1 tablespoon olive oil (15 ml)
- 1 green bell pepper (150 g), finely diced
- 1 small yellow onion (120 g), finely diced
- 1 1/2 cups diced cooked ham (210 g)
- 10 large eggs
- 1/2 cup whole milk (120 ml)
- 1 teaspoon Dijon mustard (5 ml)
- 1/2 teaspoon kosher salt (3 g)
- 1/2 teaspoon black pepper (1.5 g)
- 1/4 teaspoon smoked paprika (0.75 g)
- 1 1/2 cups shredded cheddar cheese (168 g), divided
- 2 tablespoons sliced green onions (12 g), to serve
Amounts are for the yield below. US customary measures first, grams in brackets for scale users.
Step-by-step instructions
- Heat the oven and soften the vegetables. Heat the oven to 350°F (177°C) and lightly grease a 9x13 inch (23x33 cm) baking dish. Heat the olive oil in a skillet over medium heat, add the pepper and onion, and cook for 5 to 6 minutes, until softened and sweet with no raw crunch left. Take the pan off the heat and let the vegetables cool for a few minutes.
- Whisk the egg base. Whisk the eggs, milk, mustard, salt, black pepper and paprika together in a large bowl until completely uniform and slightly frothy. A thoroughly whisked base bakes up even and tender; visible streaks of white bake into uneven patches. Do not add the cheese yet.
- Combine filling and cheese. Fold the cooled vegetables, the diced ham and 1 cup (112 g) of the cheddar into the eggs until evenly distributed. The filling should be generous in every spoonful — if the ham has settled, give the bowl one more stir as you pour. Pour the mixture into the prepared dish and level the top.
- Top and bake until just set. Scatter the remaining cheddar evenly over the top. Bake for 32 to 38 minutes, until the edges are puffed and set and the centre is just set with the faintest wobble when you nudge the dish, reading about 160°F (71°C) in the middle. If the top browns too quickly, cover it loosely with foil for the last 10 minutes.
- Rest before cutting. Rest the casserole on a rack for 10 minutes. The centre finishes setting as it stands, the cheddar settles, and the squares will cut cleanly instead of slumping. Skipping the rest is how an egg bake ends up weeping liquid onto the plate, so give it the full time.
- Serve warm. Cut into 8 generous squares, scatter with the green onions, and serve warm with toast, fruit, or a simple green salad for a brunch plate. A bottle of hot sauce on the table is traditional and entirely correct — the mild, cheesy eggs welcome it.
Nutrition estimate
| Nutrient | Per serving |
|---|---|
| Calories | 265 kcal |
| Protein | 20 g |
| Carbohydrates | 4 g |
| Fat | 18 g |
| Saturated fat | 8 g |
| Sodium | 720 mg |
| Fiber | 1 g |
| Sugar | 2 g |
Nutrition figures are estimates calculated from standard ingredient data for the yield stated. Your actual values will vary with brands, substitutions and portion sizes — treat them as a guide, not a guarantee.
Storage & reheating
Leftovers keep for up to 3 days in an airtight container in the refrigerator. Reheat squares in a 325°F (163°C) oven for 10 to 12 minutes, until warmed through — gentle heat keeps the eggs tender, while a fierce microwave makes them rubbery. Baked squares freeze for up to 2 months, wrapped individually; thaw overnight in the refrigerator before reheating. Nutrition figures are estimates from standard ingredient data and vary with brands and substitutions.
Easy Denver Omelette Casserole
Ham, peppers, onion, cheddar — diner breakfast, baked for a crowd.
Ingredients
Tick ingredients off as you prep, and tap a step below to mark it done as you cook. Scaling adjusts the listed amounts - seasoning to taste stays your call.
Instructions
- Heat the oven and soften the vegetables. Heat the oven to 350°F (177°C) and lightly grease a 9x13 inch (23x33 cm) baking dish. Heat the olive oil in a skillet over medium heat, add the pepper and onion, and cook for 5 to 6 minutes, until softened and sweet with no raw crunch left. Take the pan off the heat and let the vegetables cool for a few minutes.
- Whisk the egg base. Whisk the eggs, milk, mustard, salt, black pepper and paprika together in a large bowl until completely uniform and slightly frothy. A thoroughly whisked base bakes up even and tender; visible streaks of white bake into uneven patches. Do not add the cheese yet.
- Combine filling and cheese. Fold the cooled vegetables, the diced ham and 1 cup (112 g) of the cheddar into the eggs until evenly distributed. The filling should be generous in every spoonful — if the ham has settled, give the bowl one more stir as you pour. Pour the mixture into the prepared dish and level the top.
- Top and bake until just set. Scatter the remaining cheddar evenly over the top. Bake for 32 to 38 minutes, until the edges are puffed and set and the centre is just set with the faintest wobble when you nudge the dish, reading about 160°F (71°C) in the middle. If the top browns too quickly, cover it loosely with foil for the last 10 minutes.
- Rest before cutting. Rest the casserole on a rack for 10 minutes. The centre finishes setting as it stands, the cheddar settles, and the squares will cut cleanly instead of slumping. Skipping the rest is how an egg bake ends up weeping liquid onto the plate, so give it the full time.
- Serve warm. Cut into 8 generous squares, scatter with the green onions, and serve warm with toast, fruit, or a simple green salad for a brunch plate. A bottle of hot sauce on the table is traditional and entirely correct — the mild, cheesy eggs welcome it.
Recipe by Ahsan ul Haq · FryDaily. Printing? This card is designed to print cleanly on its own.
