Preheat the oven to 425 degrees and line a baking sheet with parchment paper.
Combine the Boursin, mayo, parmesan, spinach, artichoke hearts & dry seasonings in a bowl. Mix to combine and set aside.
Place the thawed puff pastry dough on a lightly floured surface and gently roll it out so that it is slightly larger than its original size. Transfer to the prepared baking sheet.
Use a knife to create a 1-inch border around the dough – being sure not to cut all the way through. Use a fork to score the inside rectangle of the dough. Add the spinach artichoke mixture to the center portion of the dough and spread to the edges.
Brush the edges with the melted butter and sprinkle with the everything seasoning. Place in the oven for 18-20 minutes, or until the dough is browned and crispy.
Remove from the oven and allow to cool for 5 minutes. Cut into 9 slices and serve.
Video
Notes
To thaw the puff pastry dough I like to let it sit out for 40-60 minutes. During this time I like to thaw the spinach and make the dip.
I left a couple of artichoke hearts whole to use on top of the tart.
If you can't find dairy-free Boursin you can sub vegan cream cheese.