In a small pan set over medium-low heat, combine the canola oil, chopped garlic, onions, and red bell pepper and Cajun spice. Let this mixture sit for a little bit about 5 minutes.
Bring a pot of water to a boil, then blanch the broccoli for about 1-2 minutes remove, and drain. Then toss with parts of the garlic mixture.
Arrange the broccoli in a single layer on a greased baking sheet. Roast for 16-20 minutes, until cooked through and slightly brown.
Put the roasted broccoli back in the bowl and toss with remaining garlic, onion and red pepper mixture. Adjust seasoning salt freshly ground pepper.