Special equipment: Outdoor grill, 6-ounces apple wood chips, for smoking
Shape a large piece of aluminum foil into a bowl shape. Submerge the wood chips in water for at least 15 minutes, then drain them and put them in the foil 'bowl'. If you are using a gas grill turn 1 side to high and leave the other side off.
Put the tomatoes on the side of the grill that is off and put the foil bowl full of wood chips on the heated side. Close the lid and smoke for 45 minutes.
Indoor method: Put the soaked wood chips in the bottom tray of a stovetop smoker. Heat over medium-high heat until the chips begin to smoke. Put the tomatoes, over the wood chips in the smoking tray, and then cover the smoker. Reduce the heat to medium-low and smoke for 15 minutes.
When the tomatoes are done, put them in a large mixing bowl to cool slightly. Peel the skins from the tomatoes and discard.
Add the tomatoes to a blender and blend on high until smooth, 1 to 2 minutes. Heat 1 tablespoon of the oil in a medium saucepan over medium heat and add the garlic and shallots. Saute until softened, about 4 minutes. Stir in the tomato puree and simmer until slightly thickened, 20 to 25 minutes. Season with salt, and pepper, to taste. Let the tomato mixture cool for about 5 minutes, then add it to a blender and mix until smooth. Strain through a fine sieve into a bowl and set aside.
In a coffee grinder, grind the chiles and quinoa into a powder. Season the tuna steaks with salt and pepper, to taste, and then toss them in the chile dust.
In a large heavy bottom skillet over high heat, add 3 tablespoons olive oil and heat until smoking hot. Sear all 4 sides of the tuna steaks making sure cooking time is even for all sides, about 30 seconds per side. While the grill is still hot, coat the whole scallions with remaining olive oil, and season with salt and pepper, to taste. Grill for about 1 minute on each side.
Indoor method: Char the scallions on a lightly oiled grill pan or under a broiler.
To serve, spoon some tomato puree onto each serving plate. Slice the tuna and arrange on the plates, garnished with grilled scallions.
If using a charcoal grill do the same technique but put the foil directly on top of the hot coals. This dish goes great with a simple risotto, rice or your favorite potato recipe.