Preheat oven to 375 degrees. Coat a 9 inch pie plate with cooking spray.
Place broccoli florets in microwave safe bowl with 1 Tbsp water. Cover and microwave about 2 to 3 minutes, until broccoli is partially cooked through and can pierce with a fork but is still firm. Drain.
Heat oil over medium heat in a skillet. Add onion and cook, stirring , until softens, about 4 minutes. Add minced garlic and cook for about 30 seconds, until garlic is fragrant. Remove from heat. Stir in broccoli florets and diced meat (if using).
Whisk eggs, milk, sour cream, salt and pepper together in a separate bowl. Fold in the broccoli mixture and the cheese. Spoon into the prepared pie pan.
Bake until middle is just set, and it's a golden color, about 25-30 minutes. Let stand at least 10 minutes before serving.