Heat olive oil in 10-inch nonstick skillet over medium-high heat. Sauté onions and bell peppers for 2 to 3 minutes, stirring occasionally, until crisp-tender.
Beat eggs, milk, salt and pepper in medium bowl with fork or wire whisk until well mixed. Pour egg mixture over vegetables in skillet. Reduce heat to medium. Cook 4 to 6 minutes, stirring frequently until eggs are set but still moist.
Spoon egg mixture onto warm tortillas, sprinkle with cheese, and roll up the tortillas.