Place fresh or frozen broccoli florets in microwave-safe bowl with 2 T. of water. Microwave on high until florets are crisp and tender. Cooking time may vary, so check the florets after 2 minutes. Florets must be bright green, tender, but still crisp and firm.
While florets are cooking, peel the garlic and mince finely.
Add half the chopped garlic to cold skillet with 1 t. of olive oil. Heat to medium and add ½ t. of crushed red pepper flakes (if desired) and 1 T. of butter. Sauté garlic until golden-brown and aromatic, stirring constantly to prevent garlic from burning.
Add ½ broccoli florets to pan and increase heat to medium-high. Stir broccoli constantly to prevent burning and sticking.
Cook until broccoli florets are blackened and crisp at the edges.
Remove broccoli florets from skillet and place in a large glass bowl. Cover to keep warm and set aside.
Repeat process with remaining garlic, olive oil, crushed chili flakes, and broccoli florets.
When second batch is finished, add to the bowl with original batch.
Drizzle with sesame oil, season with salt and pepper, and toss the broccoli florets to coat them completely.
Serve immediately.