Arugula Pesto, Prosciutto & Mushrooms Open Tart

1. Pulse arugula, garlic, cheese and walnuts in a food processor until smooth. Then gradually pour in the olive oil and pulse until well emulsified. Add the lemon juice. Season pesto with salt and pepper to taste and mix again to combine. You will get approximately 1 cup of pesto but you only need 6-8 tablespoons for this tart. Keep the rest refrigerated for up to 3 days or freeze it if desired.

2. Preheat the oven to 395 F and line a baking sheet with parchment paper.

3. According to the packaging directions, if required, roll out the pastry slightly on a lightly floured surface. Transfer to the lined baking sheet and prick the pastry all over with a fork. Lay another sheet of parchment paper on the puff pastry and place a second baking sheet on top. Put the sheets into the oven and bake the pastry for 15-20 minutes, until golden. Remove the top sheet and discard the paper, then put it back in the oven and bake for 5 minutes more or until crisp and dry. Remove from oven. Cool slightly. Keep the oven on.

4. Next you will cook the mushrooms. Kitchen tip: Sear the mushrooms in batches and don’t crowd the pan; otherwise they will steam. You want to see nice golden-brown results. You can sear the mushrooms up to 2 days in advance then keep refrigerated until ready to use. Heat the oil in a large saute pan on medium-high heat. Cut any of the larger mushrooms into bite sized pieces. Add some of the mushrooms (I recommend Alba & Brown Clamshell, Forest Nameko and Velvet Pioppini varieties) into the pan and saute for 4-5 minutes until nicely browned on all sides. Season well with some sea salt and freshly ground black pepper. Transfer the mushrooms to a plate that you’ve lined with paper towel to absorb the extra oil.

5. Spread 6-8 tablespoons of the arugula pesto over the pastry, leaving a ½ inch border. Scatter some baby arugula and/or baby kale leaves on top. Tear the prosciutto into bite size pieces and lay it over the pastry. Scatter seared mushrooms in between the pieces of prosciutto and sprinkle generously with Parmesan cheese on top. Lightly beat the egg yolk and use it to brush the pastry border. Season with a pinch of red pepper flakes. Bake for 5-8 minutes until the cheese melts. Remove from oven, cool for a couple of minutes before slicing, then serve.