Preheat oven to 350°.
Heat oil in a large nonstick skillet over medium-high heat. Add onion and garlic; sauté 1 1/2 minutes. Add broccoli; sauté 1 minute. Spread broccoli mixture into a 9-inch pie plate coated with cooking spray. Combine milk and next 8 ingredients (milk through eggs) in a large bowl. Pour milk mixture over broccoli mixture; sprinkle with Parmesan. Bake at 350° for 40 minutes or until top is golden and a knife inserted in center comes out clean; let stand 5 minutes. Serve with toast.