Smash Burgers with a Cast Iron Grill Press
Fast, crisp-edged and luxuriously juicy, smash burgers made on the Big Green Egg with a cast iron grill press deliver big flavour in just minutes — simple cooking, done properly.
This method focuses on mince selection, high heat setup, a strong pressing technique and quick seasoning to maximise crust formation.
Ingredients
Patties & Buns
| 640 g | Beef mince (80/20 fat; see tips) |
| 4 | Soft burger buns (brioche or potato) |
| 8 slices | American or Colby cheese |
| 1 tbsp | Neutral oil or beef tallow |
| 2 tbsp | Butter, softened (for buns) |
| 1 tsp | Fine sea salt |
| ½ tsp | Freshly ground black pepper |
Optional Toppings
| 1 | Brown onion, thinly sliced |
| To serve | Pickles |
| To serve | Lettuce leaves |
Quick Sauce (optional)
| ⅓ cup | Mayonnaise |
| 1 tbsp | Tomato sauce |
| 1 tsp | Yellow mustard |
| 1 tsp | Pickle juice |
Equipment
| Cast-iron flat plate or heavy skillet | |
| Cast iron grill press or heavy spatula | |
| Stiff metal scraper/spatula | |
| Baking paper squares | |
| Salt shaker |
Method
Prep
- 1 Heat the plate: Preheat a cast-iron flat plate or heavy skillet over high heat (230–260°C). Allow it to get smoking hot for proper crust formation.
- 2 Make the sauce (optional): Mix mayo, tomato sauce, mustard and pickle juice. Set aside.
- 3 Portion the mince: Divide mince into 8 balls (about 80 g each). Keep them loosely packed — do not overwork. Chill while the plate heats.
- 4 Toast buns: Butter the cut sides and toast on the hot plate until golden. Set aside.
- 5 Cook onions (optional): Add a little oil and cook onions over medium heat until soft and lightly browned, 6–8 minutes. Move to a warm spot.
Smashing & Searing
- Lightly film the hot plate with oil or tallow. Place 2 mince balls down, spaced apart.
- Top each ball with a small square of baking paper and press firmly with a spatula or cast iron grill press to 6–8 mm thick. Hold for 10 seconds, then remove the paper.
- Immediately season with salt and pepper.
- Cook without moving for 90 seconds to 2 minutes until deeply browned with lacy, crispy edges.
- Scrape fully under the crust, flip, top with cheese and cook for 45–60 seconds.
- For doubles, stack one patty onto the other on-plate to melt the cheese thoroughly. Repeat with remaining balls.
Build & Serve
- 1 Sauce the bottom bun generously.
- 2 Add pickles, then the stacked patties.
- 3 Top with caramelised onions and/or lettuce if using. Cap with the top bun and serve immediately.
Mince selection: 80/20 beef is ideal for flavour and juiciness. High heat: Preheat cast iron well — thin patties cook fast and need intense heat. Pressing technique: Press once, hard, and hold; avoid pressing after flipping. Crust formation: Do not move the patty until a deep brown edge forms. Bun toasting: Toasted, buttered buns resist sogginess and add great texture.
Variations
| Single patty | Use 100–120 g balls and skip the stacking step |
| Onions-on-top | Scatter thin onions on the patty before smashing for diner-style caramelised onions |
| Veg option | Try smashed black bean or mushroom patties using the same smash-and-sear approach |
Serving & Storage
| Serve with | Chips, slaw or onion rings |
| Fridge | Store cooked patties up to 3 days chilled |
| Reheat | On a hot plate for 30–60 seconds per side |
| Freezer | Freeze raw portioned balls on a tray; thaw overnight in the fridge before cooking |
FAQ
What fat ratio works best?
80/20 delivers the best balance of flavour, moisture and crust. Leaner mince tends to dry out quickly on a smoking-hot plate.
How do I stop the patty sticking?
Use a ripping-hot plate, a light oil film and a baking paper square while pressing. Once a proper crust forms, the patty releases cleanly on its own.
Do I need a grill press?
A heavy spatula works in a pinch, but a cast iron grill press gives consistent thickness, better surface contact and a more even crust across the whole patty.
Can I use lean mince?
It will be drier and less flavourful. If using leaner mince, add a little beef tallow to the plate to compensate for the reduced fat content.
Are smash burgers cooked through?
Yes. Thin patties cook very fast at high heat and are typically well-done throughout while still remaining juicy thanks to the fat content.
Got questions about setup, heat control or accessories for your Big Green Egg? Contact us for expert advice and gear recommendations.