Preheat a grill or grill pan to medium high. Brush a baking sheet with olive oil. Form the pizza dough into a 9-by-12-inch oval on the baking sheet; cover loosely with plastic wrap and set aside.
Heat 1 tablespoon olive oil in a large skillet over medium heat. Add the pancetta and cook, stirring occasionally, until crisp, about 6 minutes. Transfer to a paper towel-lined plate to drain.
Combine the Asiago, Parmesan and garlic in a bowl; set aside. Brush the grill or grill pan grates with olive oil. Generously brush the top of the dough with olive oil and place on the grill grates; grill until golden on the bottom, 4 to 5 minutes. Flip and continue grilling until marked, about 2 more minutes. Loosen the crust with a spatula, then top with the cheese mixture. Cover and cook until the cheese melts, 3 to 4 minutes. Transfer to a cutting board.
Meanwhile, combine the fennel, escarole, the remaining 2 tablespoons olive oil, the vinegar and red pepper flakes in a bowl; season with salt and pepper and toss. Scatter the salad over the pizza and top with the pancetta; season with salt. Cut into pieces.