Preheat oven to 350 degrees F (175 degrees C). Grease a 9-inch pie plate.
Heat a large skillet over medium-high heat and stir in sausage. Cook and stir until sausage is crumbly, evenly browned, and no longer pink, about 10 minutes. Drain and discard any excess grease.
Place four tortillas in prepared pie plate, overlapping and extending 1/2-inch beyond rim; place remaining tortilla in center. Layer sausage, Monterey Jack cheese, Cheddar cheese, and green chilies over tortillas. Combine eggs, heavy whipping cream, ricotta cheese, and chili powder in a bowl; slowly pour egg mixture into pie plate.
Bake in preheated oven until center is set and puffed, about 45 minutes. Sprinkle with cilantro and cut into wedges.