Zucchini Gratin, Heaped and Bubbling

A heaped, bubbling individual zucchini gratin in a white ramekin, golden panko-parmesan crust over tender zucchini in a creamy sauce.
Heaped and bubbling over, exactly how an individual gratin should look.
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Adapted, with love and a few opinions, from Ina Garten’s Zucchini Gratin.

I adore Ina, and I’ve cooked my way through a good many of her recipes, but this one (in my humble opinion) needed more. And less. More spice, less butter. More zucchini, less onion. More garlic (there’s none at all in hers, though I’ve since learned to use a gentle hand; this dish over-garlics fast). None of this is a knock on the Barefoot Contessa; it’s just what my kitchen wanted on the day.

  • Sliced zucchini and onion on a cutting board with a mandoline, prepped for zucchini gratin.
  • Zucchini and onion in a creamy spiced sauce cooking in a cast iron skillet, the base for zucchini gratin.

There was one wrinkle, and it’s the instructive kind: today I made it with only two zucchini, and it came up a ramekin short (and a little onion-forward for my taste). Next time I’ll use three, which is how I’ve written the recipes. Three gets the squash-to-onion ratio right and gives you enough filling to properly heap all four ramekins. Because the entire point of serving something like this in little individual ramekins (at least for me) is to make it look indulgent and generous. A flat, leveled, politely browned ramekin is a sad ramekin. It needs to be heaped and bubbling over.

Those ramekins, by the way, are the little French-white au gratin dishes I pulled out of the Goodwill on Holcomb Bridge Road last week during my thrift haul; four of them at $2.24 apiece. This is the exact job I bought them for, and I’m delighted to report they delivered.

  • Four ramekins of zucchini gratin topped with an even layer of panko and parmesan, ready to bake.
  • Four individual zucchini gratins on a sheet pan with golden-brown panko-parmesan tops, fresh from the oven.

Being a ramekin short today, I didn’t let the extra topping go to waste either. I spooned the leftover breadcrumb mixture into that empty fourth ramekin and toasted it up alongside the others while they baked. I can always find a use for a little toasted panko and parm (it’ll probably land on tomorrow’s salad, for crunch).

Notes

  • Heap them: if you’re using individual ramekins, mound the filling generously. Flat and level is fine; heaped and bubbling over is the whole point. (Three zucchini, not two, is what fills all four properly.)
  • Garlic, but gently: this dish does want garlic (Ina’s has none), but it over-garlics in a hurry. One or two cloves, not a whole head.
  • The parm matters: deli parm, grated fresh, is a completely different food than the shelf-stable green-can stuff. This is the place to spend the extra dollar.
  • Don’t waste the topping: any leftover panko-parm mixture toasts up beautifully in a spare ramekin and lives happily on the next day’s salad.
  • Make it a skillet: short on ramekins (or patience)? Bake the whole thing in the cast iron and scoop it family-style.
  • The rest isn’t optional: ten minutes out of the oven, every time. It sets the sauce and saves your mouth.
A heaped, bubbling individual zucchini gratin in a white ramekin, golden panko-parmesan crust over tender zucchini in a creamy sauce.
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Zucchini Gratin

Adapted from Ina Garten’s Zucchini Gratin. Serves 4 in individual ramekins, or one 12-inch skillet.

Ingredients

  • 1 large yellow onion halved and sliced (about ½ lb)
  • 3 large zucchini large, not huge, not woody, sliced to about ⅛” (thickest mandoline setting)
  • 1-2 cloves garlic minced or pressed (go easy; this dish over-garlics fast)
  • 2 tbsp olive oil
  • 3 tbsp flour
  • 1-2 tsp kosher salt to taste
  • 1 tsp smoked paprika
  • 1 tsp mustard powder
  • 1-2 bay leaves
  • 1 cup warm milk 2% is fine; I used whole because that’s what I have

For the topping

  • 3 tbsp butter I used salted; you do you, melted
  • ¾ cup panko or breadcrumbs
  • ¼ to ⅓ cup grated parm please don’t use the green can; get the real stuff from the deli

Instructions

  • Preheat. Get the oven to 400°F.
  • Cook the vegetables. Heat the olive oil in a large pan (I used my 12-inch cast iron) over medium-high heat. Add the onions, and right when they start to turn translucent, add the garlic and zucchini. Cover and cook about 5 minutes, until the zucchini starts to darken, then uncover and cook a further 5 to 10 minutes to let some of the moisture evaporate.
    1 large yellow onion, 1-2 cloves garlic, 2 tbsp olive oil, 3 large zucchini
  • Make the roux base. Meanwhile, whisk the flour and spices together, and warm your milk (90 seconds in the microwave worked perfectly for me).
    3 tbsp flour, 1-2 tsp kosher salt, 1 tsp smoked paprika, 1 tsp mustard powder, 1-2 bay leaves
  • Build the sauce. Sprinkle the flour-and-spice mixture evenly over the cooking zucchini and onions and stir well. Add the milk and keep stirring and scraping, making sure all the zucchini is evenly coated. Reduce the heat to low and let it thicken.
    1 cup warm milk
  • Fill. Spoon into individual ramekins (heaped, please), or leave the whole mixture in the pan and bake it right in the skillet if it’s oven-safe.
  • Top. Mix the panko, parm, and melted butter, and layer it over the top of the zucchini.
    3 tbsp butter, ¾ cup panko or breadcrumbs, ¼ to ⅓ cup grated parm
  • Bake. 15 to 25 minutes (less for the ramekins, more for the full skillet), until the crumb topping is golden brown and the filling is bubbling up around the edges.
  • Rest. Cool for 10 minutes before serving. I know it’s tempting to dive right in; trust me, wait the 10. The sauce thickens as it cools, which means you get that lovely clean cross-section, and you (or your guests) won’t take a bite of molten sauce and sear the roof of your mouth. Ten minutes. The anticipation is worth it.

Notes

  • Heap them: if you’re using individual ramekins, mound the filling generously. Flat and level is fine; heaped and bubbling over is the whole point. (Three zucchini, not two, is what fills all four properly.)
  • Garlic, but gently: this dish does want garlic (Ina’s has none), but it over-garlics in a hurry. One or two cloves, not a whole head.
  • The parm matters: deli parm, grated fresh, is a completely different food than the shelf-stable green-can stuff. This is the place to spend the extra dollar.
  • Don’t waste the topping: any leftover panko-parm mixture toasts up beautifully in a spare ramekin and lives happily on the next day’s salad.
  • Make it a skillet: short on ramekins (or patience)? Bake the whole thing in the cast iron and scoop it family-style.
  • The rest isn’t optional: ten minutes out of the oven, every time. It sets the sauce and saves your mouth.

P.S. Ina, if you ever read this: still a devoted fan, just a bossy one. The garlic was always going in (gently).

P.P.S. The sad empty ramekin in one of these photos isn’t sad at all; that’s where the extra topping went to become tomorrow’s salad crunch. Nothing wasted.