• Place oven racks so that oven is evenly divided into thirds. Place empty baking sheet on top oven rack and preheat broiler on High.

For the Fajita Veggies

• In small bowl, mix together avocado oil, garlic, chili powder, lime juice, oregano, cumin, and salt.
• Place sliced peppers and onions in large bowl. Pour half of avocado oil mixture over veggies and toss well to coat.
• Carefully and quickly, remove baking sheet from oven and transfer marinated peppers and onion to baking sheet. Return baking sheet to oven and cook on top rack under broiler for 7 minutes, or until veggies begin to soften and brown.

For the Guacamole

• While peppers and onions are in oven, make guacamole by adding all guacamole ingredients to small bowl. Mash to desired consistency and taste, adding more salt as desired. Set aside or chill until ready to serve.

For the Fajita Steak

• Place sliced steak in large bowl that was used for peppers and onions. Top with remaining avocado oil marinade and toss well to coat.
• After peppers and onions have cooked 7 minutes (or until softened and browned), carefully and quickly remove baking sheet from oven. Use tongs to rearrange pan, creating space between peppers and onions. Place marinated steak in spaces in one flat layer, being careful not to overlap or overcrowd.
• Return baking sheet to oven. Cook 4 minutes, or until steak is uniformly browned on top. Steak will likely show medium-rare temperature on underside, not on top, so carefully use tongs to flip steak and check doneness. Add additional time as needed to reach desired doneness.

To Serve

• Carefully remove baking sheet from oven. Garnish with guacamole and toppings as desired. Serve fajita vegetables and steak as-is, in burrito bowls with cauliflower rice, or with lettuce cups or tortillas (if not on Whole30).