Heat oven to 425°F. Spray 1 1/2-quart casserole with cooking spray.
In a large skillet, heat oil over medium heat. Add onion and garlic and cook until onion is tender, 3-4 minutes.
Add kale and cook until wilted, about 8-10 minutes
In large bowl, beat cream cheese, mayonnaise and milk until smooth.
Add salt, pepper and hot sauce.
In a small bowl combine the cheddar, Monterey Jack and Parmesan cheeses
Add kale mixture and 1/2 of the cheese to the cream cheese mixture.
Spoon into prepared casserole dish. Sprinkle with remaining cheese
Bake uncovered until golden and bubbly, about 30 minutes.