Turn a slow cooker (such as Crock Pot(R)) on High; coat lightly with cooking spray. Fill with processed cheese, mushroom soup, diced tomatoes with green chiles, evaporated milk, sour cream, milk, and cream cheese. Cover with the lid. Cook until mostly melted, about 1 hour. Heat oil in a skillet over medium-high heat. Saute poblano peppers, yellow onion, and jalapeno peppers until softened, about 5 minutes. Transfer vegetables to the slow cooker; add green chiles, garlic, and cilantro. Cover and continue cooking until cheese is completely melted, about 20 minutes. Add the Mexican cheese blend; stir until heated through, about 10 minutes more.