Directions for the Onions
1. Peel and slice the onions thin.
2. In a large, wide saute pan (roughly 14") over medium high heat add the oil.
3. Once the oil is hot add the onions and toss to evenly coat with the oil
4. Turn the heat down to low and cook about one hour, stirring every 10 minutes until caramelized.
5. Set aside. You can prepare these as much as 3 days in advance.
Directions for the Tomatoes
1. Pre-heat oven to 300.
2. Slice each tomato into 5 slices (they will be roughly 1/2" thick.
3. lay tomatoes out evenly on a sheet pan (a silpat or non-stick pan is best).
4. drizzle with olive oil, season with salt.
5. Bake for two hours until slightly less than half the original size. You want them to be wrinkled and concentrated but still juicy.
Directions for the Cabbage
1. Slice the cabbage thin. Squeeze in lime and stir in salt.
2. Best to use a large bowl or wide dish so that the cabbage can "pickle" evenly.
3. Set in fridge for at least 30 minutes and up to 2 days.
Directions for Tuna
1. Mix spices together. I like to use whole seeds and crush slightly. You don't have to crush. This yields a great texture on the tuna but you can also use ground spices if that is all you have.
2. Salt the tuna to taste.
3. Coat both sides of each tuna filet with the spice mixture.
4. In a thick bottom saute pan big enough for the four filets add the oil over medium high heat.
5. Once the oil is hot add the tuna filets. Cook until golden with a nice crust. Flip, cook the other side until golden. About 4 minutes total cooking time. You want to keep the center rare (unless you prefer it otherwise).
Directions for Harissa
1. Grind together in a mortar or food processor.
Build the sandwiches:
Bottom bun - 5 oven dried slices -tuna filet - caramelized onions - cabbage - spread harissa on top bun and place on top.