For the spread: Preheat oven to 350° F. In a glass pie plate or 8 × 8” baking dish thoroughly mix together all ingredients using a fork to mash the roasted garlic cloves and break up the artichoke hearts. Cover with aluminum foil, bake 25-30 minutes until bubbly. Spread will keep 2-3 days covered in refrigerator.
For the roasted garlic: Preheat oven to 400° F. Using a sharp serrated knife cut off the pointy top (approximately ¼ inch) of a whole unpeeled head of garlic, revealing the individual cloves within. Wrap garlic head tightly in aluminum foil leaving the cut side exposed, place in an ovenproof dish then drizzle exposed cloves with 1½ tablespoons olive oil. Bake 30-45 minutes until garlic head is soft, slightly golden, and cloves slide easily from their papery coverings when pinched.
To make the pizza: Heat your grill completely, then either bank coals to one side if using a charcoal grill or turn off one of the burners if using a propane grill. This creates an indirect heat space and closing top vents will help create a convection.
Flatten and shape pizza dough, dusting each side generously with cornmeal and working until the crust is ¼ - ⅛ inch thick. Brush top side with olive oil, then flip oiled side of dough onto the grill where the heat is indirect. Close lid of grill and allow to cook 3-4 minutes, rotate crust 180 degrees using tongs and allow to cook for an additional 3-4 minutes until crust is golden on the bottom with visible grill marks.
Toss sliced salmon in a bit of olive oil to coat and salt lightly. Remove crust from grill and top the grilled side of the crust beginning with the spread, withholding only the mizuna or arugula for garnish once pizza is done.
Return the pizza to the grill’s indirect heat space, close the lid, and allow to cook for 3-4 minutes. Rotate pizza 180 degrees and cook for another 3-4 minutes until the cheese is completely melted. If needed, slide pizza over direct heat to finish. Top with your greens and serve immediately.