Preheat the oven to 500 degrees F and place a rack on the bottom shelf.
Place 2 cups of the kimchi and the pear into the bowl of a food processor. Blend to a chunky puree.
Drain the liquid from the remaining kimchi into the food processor, and then chop into bite-size pieces.
Cook the bacon in a large saute pan over medium heat until crispy and most of the fat has rendered, 12 to 15 minutes.
While the bacon is cooking, roll out the pizza dough. Cut a piece of parchment paper to fit the back of an inverted baking sheet. Place the baking sheet in the oven on the bottom shelf. Lightly dust the parchment with flour. Divide the dough in half, and then stretch or roll 1 piece of dough into an 11-inch round directly on the parchment paper.
Once the bacon is crispy, use a slotted spoon to transfer half of the bacon to a paper-towel-lined plate to drain. Add the kimchi puree to the remaining bacon in the pan. Stir to combine. Bring to a boil over medium-high heat, and then reduce to a simmer. Simmer, uncovered, until slightly thickened, stirring occasionally, about 5 minutes. Stir in 1 teaspoon of the sesame oil. Season with salt and pepper.
To assemble 1 pizza, spread half of the kimchi sauce on the dough, leaving a 1/2-inch border. Sprinkle half of both cheeses over the kimchi sauce. Spread half of the chopped kimchi over the cheese. Brush the crust with half of the remaining sesame oil and sprinkle with half of the sesame seeds.
Carefully lift the parchment onto the heated baking sheet. Cook until the crust is golden brown and the cheese is bubbly, 8 to 12 minutes. Remove from the oven. Allow to cool on the baking sheet for 5 minutes before serving. Sprinkle with half of the reserved bacon and garnish with some sliced scallions.
Repeat with the remaining ingredients to make 1 more pizza.