Cook sausage and bell peppers in large nonstick skillet over MEDIUM heat 5-6 minutes or until sausage is thoroughly heated, stirring frequently. Remove from skillet; cover to keep warm.
Beat eggs and milk in large bowl with wire whisk until well blended. Melt butter in same skillet over MEDIUM-LOW heat. Add eggs; cook and stir 6-8 minutes or just until set. Stir in sausage mixture; cook 1-2 minutes or until thoroughly heated. Remove from heat.
Top each tortilla with about ½ cup egg mixture, ½ cup cheese and 2 tablespoons cilantro.