1. Preheat oven to 400ºF. Warm oil in a skillet over medium heat. Add onion, sprinkle lightly with salt and cook, stirring occasionally, until softened, 3 to 5 minutes. Add garlic, chili powder, cumin and a pinch of salt and sauté 30 seconds longer. Add turkey and cook, stirring and breaking up meat with a wooden spoon, until cooked through, 5 to 7 minutes.
2. Spread 1/2 bag of chips in a single layer in a 9-by-13-inch baking dish. Spoon 1/2 of turkey mixture over chips. Spread 1/2 of beans and 1/2 of cherry tomatoes over turkey. Sprinkle with 1/2 of cheese. Repeat with remaining chips, turkey, beans, tomatoes and cheese. Bake uncovered until cheese is melted, 7 to 10 minutes. Serve immediately.