1. Preheat oven to 425 degrees Fahrenheit (220 degrees Celsius).
2. Place broccoli in a strainer and rinse under running water. Transfer to a 9×13-inch baking pan. Drizzle with flavored olive oil, kosher salt, pepper, and lemon juice. Toss to coat. Bake for 20 minutes, turning once.
3. While broccoli is baking, prepare the crumbs: Melt margarine in a small frying pan over medium heat. Sauté the onions until they are almost translucent, around 10 minutes.
4. Add the crushed garlic and continue to sauté an additional five minutes. The mixture will become a light golden.
5. Add in panko crumbs and toss until crumbs are golden. Stir in basil until well mixed. Pour in lemon juice and mix well. Remove from heat.
6. Sprinkle prepared crumbs over the broccoli bake. Toss until well coated.