Grill poblano and Anaheim peppers, without grill lid, over medium-high heat (350° to 400°) 5 to 7 minutes or until peppers look blistered, turning often.
Place peppers in a heavy-duty zip-top plastic bag; seal and let stand 10 minutes to loosen skins. Peel peppers; remove and discard seeds. Slice peppers into thin strips.
Sauté onion and garlic in hot oil in a large skillet over medium-high heat. Add pepper strips, and cook 2 minutes or until tender; reduce heat to low. Add cheeses and half-and-half, stirring until cheese is melted. Serve warm with tortilla chips. Garnish, if desired.
Note: For testing purposes only, we used Velveeta for cheese product.