Gruyere Feta Souffle

Wall Street Journal. As of this writing I've never tried making a souffle. Recipe makes individual souffles in 6-oz ramekins. It also calls for nasturtium leaves and says you can substitute chives. I'll never be able to find nasturtium leaves.

Ingredients

4 tablespoons unsalted butter, plus more for greasing ramekins
1 tablespoon Parmigiano Reggiano, finely grated, plus more for dusting ramekins
1/4 cup all-purpose flour
1 cup whole milk
3/4 cup cave-aged Gruyère or aged cheddar, finely grated
1/3 cup Feta, very finely crumbled
1/4 teaspoon cayenne pepper
Freshly ground black pepper
3 tablespoons nasturtium leaves or chives, finely chopped
2 tablespoons fresh flat-leaf parsley, finely chopped
4 large eggs at room temperature, separated
1/4 teaspoon cream of tartar (optional)

Instructions

1. Preheat oven to 350 degrees. Fill a kettle and set it to boil. Generously grease 6 (6-ounce) ramekins with butter and lightly sprinkle each with Parmigiano. Place prepared ramekins in a roasting pan.

2. Make the béchamel: In a heavy-bottomed saucepan over medium heat, melt butter. Add flour and whisk until bubbling and smooth. Whisking constantly, add milk and cook until thickened, about 3 minutes. Remove from heat, and add Parmigiano, Gruyére, feta, salt, cayenne, pepper, nasturtiums and parsley, and whisk to combine. Transfer to a mixing bowl and let cool.

3. Whisk egg yolks, one at a time, into béchamel. In a scrupulously clean, dry mixing bowl, combine egg whites and cream of tartar, if using. Use an electric mixer with whisk attachment to whisk on high speed until peaks form. (Don’t let them get dry and grainy.)

4. Use a flexible spatula to gently fold a third of egg whites into béchamel until incorporated. Add another third, then repeat with remaining third, until you have a lovely, airy mixture.

5. Fill prepared ramekins, leaving 1/2-inch of space at top. Place roasting pan in oven, then carefully pour boiling water into pan until water reaches halfway up ramekins.

6. Bake until golden and puffed, about 25 minutes. Do not open the oven as these bake. Serve immediately.