**Leek & parmesan frittata with butter-fried croutons** — uses everything, one pan plus a frying pan, done in ~18 min.

**Prep (3 min)**
- Slice the leek and rinse it well in a bowl of water (leeks hide grit — swish and lift out, don't just run under the tap).
- Beat the 4 eggs with a big handful of grated parmesan, salt, pepper.
- Cube the stale bread.

**Cook**
1. Melt a good knob of butter in a frying pan, medium-low. Cook the leek 5–6 min until soft and sweet, not browned. Season.
2. Meanwhile, in a second pan, fry the bread cubes in butter until golden and crisp. Set aside on a plate.
3. Pour the eggs over the leeks, stir once, then low heat with a **lid on** (this replaces the oven) for 6–8 min until just set — slightly wobbly in the middle is perfect, it'll finish off-heat.
4. Shower with more parmesan, slide onto plates, croutons on top or alongside.

**Tips**
- No lid? A plate or baking sheet over the pan works.
- Want it fancier: dollop of anything creamy (ricotta, sour cream) on top if you have it.
- One heads-up: traditional Parmigiano-Reggiano is made with animal rennet, so strict vegetarians skip it — if that matters to your gf, check the label; lots of generic "parmesan-style" cheeses use vegetarian rennet.

Backup plan if the frittata sticks: just scramble the whole thing in the pan with the croutons mixed in — basically leek migas, still delicious.