Heat oven to 350ºF.
Cook and stir tomatillos and garlic in large nonstick skillet on medium-high heat 4 min. or until tomatillos are evenly browned. Add 1/2 cup water; cover. Cook 5 min. or until tomatillos are softened and water is evaporated; transfer to blender. Add remaining water, peppers, half the cilantro and salt; blend until smooth. Stir in 1/3 cup onions.
Cook chorizo in same skillet on medium heat 4 to 5 min. or until done; drain. Stir in eggs; cook 2 min. or just until eggs begin to set, stirring occasionally. Gently stir in half the VELVEETA.
Spread 3/4 cup tomatillo sauce onto bottom of 13×9-inch baking dish sprayed with cooking spray. Spoon about 1/3 cup egg mixture down center of each tortilla; roll up. Place, seam-sides down, in dish. Top with remaining VELVEETA and tomatillo sauce.
Bake 20 min. or until enchiladas are heated through and VELVEETA is melted. Finely chop remaining cilantro. Serve enchiladas topped with sour cream, remaining onions and cilantro.