The night before, toast almonds in a pan or oven till nicely amber in colour and soak overnight in 250ml water. Take sirloin out of the packet and leave uncovered overnight or 24 hours on a rack in the fridge.
Take the steak out of the fridge, oil with a little canola oil and season with salt and pepper (3 parts salt to 1 part pepper ratio.)
Drain soaked almonds over the crusty bread leaving the bread to soak in the juice and the vinegar. Blend almonds in a blender for 30 seconds and then add the soaked bread, leftover soaking mixture, garlic, lemon and salt. Blend all ingredients for 1 minute. Once combined, add oils to emulsify into a chunky puree. Taste for seasoning and zing. Cover and set aside.
Rub all vegetables in a little vegetable oil and season lightly with salt. Grill over a high heat on the BBQ. Blacken the capsicums and chillis and "burn" the tomatoes until well charred. Slowly grill the onion and the garlic to cook out the rawness. Once the capsicum and chillis are blackened, put in a bowl and cover for 10 minutes to steam off the skins.
Place onion, tomatoes and squeezed out roasted garlic in the food processor. Rub the skins off the capsicums and chillis and de-seed. Place in the food processor. Pulse together with the olive oil, fresh garlic and salt. This should be a rough, chunky salsa, not a puree.
Take the steak and place on the hottest part of the BBQ. Flip every two minutes until at your desired doneness to ensure an even cook.
Rest the steak for half the time you cooked it (use a wired rack to ensure it doesn’t sit in juices and continues to cook on plate, which can result in overcooking).
Leaving the steak in the fridge overnight dries the steak out slightly giving it a better crust, texture and flavour.
Use canola oil not olive oil to cook the steak as it has a higher smoking point so won’t leave a bitter taste.
If you prefer a spicier salsa, leave the seeds in one or more of the chillis.
Suggest using sea salt flakes to season as It melts better Into the steak when cooking.