Spray 4- to 5-quart slow cooker with cooking spray. In cooker, beat eggs, salt, pepper and half-and-half with electric mixer on medium speed until smooth. Sprinkle with ham.
Cover; cook on High heat setting 1 hour, stirring after 30 minutes.
Continue cooking 40 to 50 minutes longer, stirring every 10 minutes, until eggs are moist and almost cooked through.
In 10-inch skillet, melt butter over medium heat. Add green onions and bell pepper; cook about 5 minutes, stirring occasionally, until pepper is tender. Stir pepper mixture and cheese into eggs. Serve immediately, or reduce to Low heat setting and hold up to 1 hour.