Portobello Parmesan Sandwich with Rosemary Mayonnaise

• 2 tablespoons fresh lemon juice
• 1 tablespoon fresh rosemary leaves
• 1 large egg yolk
• Kosher salt and freshly ground black pepper
• 3/4 cup grapeseed or other neutral oil
• 1/4 cup extra-virgin olive oil, plus more as needed
• 4 large portobello mushroom caps
• 4 kaiser rolls, split
• Pickled Long Red Chiles (page 248), to taste
• 2 cups loosely packed arugula leaves
• 1-ounce block Parmigiano-Reggiano cheese

1. Set the oven rack 6 inches from the broiler heat source.
2. Preheat the broiler to high.
3. Process the lemon juice, 1 tablespoon water, and the rosemary in a food processor until the rosemary is finely chopped.
4. Strain through a fine-mesh sieve, pressing on the solids to extract as much liquid as possible, and return the liquid to the processor; discard the solids.
5. Add the egg yolk and 3/4 teaspoon salt and process until smooth.
6. With the machine running, add the oils in a steady stream and process until emulsified.
7. Arrange the mushrooms in a single layer on a rimmed baking sheet.
8. Season both sides liberally with salt and pepper.
9. Drizzle generously with olive oil, turning to coat.
10. Turn the mushrooms gill side up and broil for 8 minutes, then flip and broil until tender, about 3 minutes longer.
11. Cut each mushroom into 4 slices at an angle, keeping each cap together.
12. Toast the rolls and spread the rosemary mayonnaise on both cut sides of each roll.
13. Arrange a mushroom, gill side up, on the bottom of each roll and top with chiles, then arugula.
14. Use a vegetable peeler to shave the cheese directly onto the arugula.
15. Cover with the roll tops, cut each sandwich in half, and serve immediately.

lemon juice, rosemary, egg yolk, kosher salt, grapeseed, extravirgin olive oil, portobello mushroom, kaiser rolls, red chiles, arugula, cheese

Taken from www.epicurious.com/recipes/food/views/portobello-parmesan-sandwich-with-rosemary-mayonnaise-390663 (may not work)