Preheat oven to 425°F.
Combine the tomatillos, jalapeño, cilantro, garlic, salt, pepper, agave or honey and lime juice in a high-power blender or food processor and purée into raw sauce.
Cut the chicken breasts open across the breast horizontally with a sharp knife to butterfly then open breasts and pound very thin into 4 large cutlets. These will serve as your “crust” for the pizzas.
Heat a large skillet over medium-high heat. Season chicken with salt and pepper, cumin, coriander, Mexican oregano or marjoram, and cook them 1-2 at a time in a thin layer of olive oil until lightly browned on both sides; arrange on 2 baking sheets. Top the chicken with the green sauce and lots of cheese and red onions. Bake about 12 minutes to bubbly and brown, switching baking sheets between the upper and lower racks midway.
Garnish each pizza with pickled jalapeños and cilantro leaves. Drizzle with Mexican crema and serve.