Pre-heat oven to 375 °F.
Toast fennel seeds in a small skillet over medium-heat until lightly browned and aromatic, about 2 minutes. Transfer to a mortar and pestle or spice grinder and grind until coarsely crushed.
Place 2 Tbsp. garlic, 2 Tbsp. canola oil, chili flakes, rosemary, sage, thyme and crushed fennel seeds in a bowl. Combine into a paste for marinating the roast.
Rub the roast with the marinade mixture, season with salt and pepper and place on a rack inside a roasting pan. Place in oven and cook the roast until probe thermometer reaches 145°F, about 40 minutes.
While the roast is cooking, place olive oil in a small pan and add 2 Tbsp. garlic. Heat over medium-low heat until garlic turns brown and you can smell the aromatics of the garlic. Remove from pan, place into a heat proof container and allow to cool.
Remove the roast from the oven and let rest on a separate rack in a warm place for about 10 minutes. After the roast has finished resting, slice into thin pieces and toss with pan drippings. Season with salt and pepper.