Sous-B-Q™: Tomatoes and Onions
About
The fusion of sous vide methodology and precisely temperature controlled natural smoke applied to common vegetables creates a uniquely hearty and satisfying salad.
Ingredients
Onion, large, 1 ea.
Tomatoes, medium, 5 ea.
Butter lettuce, 1 head.
S+P, to taste
Extra virgin olive oil, 3 oz./90 ml.
Balsamic vinegar, 1.5 oz./45 ml.
Equipment requirements
Immersion circulator, portable or stationary.
Heat rated container, minimum of 2 gallons/8 liters.
Heat rated sous vide bags.
Flat bottomed skillet, approximately 12″/30 cm. and 3″/90 mm deep.
Kitchen tongs, metal.
Infrared or probe thermometer.
Instructions
Level of difficulty 2
Procedure:
Seal the onion in a vacuum bag and sous vide process the onion at 183 F/84 C for 1 hour. Shock cold in iced water until it achieves 70 F/21 C. Refrigerate at 40 F/4 C or continue.
Cut the tomatoes in half against the core and use the point of a small knife to remove the seeds. Vacuum seal the tomatoes and vacuum chambe. If you do not have a vacuum chamber, gently press them between cheesecloth or even paper towels. Use a propane torch, salamander or broiler element from above (most ovens have them) to scorch the skins of the tomatoes. Allow to cool. Use a dry paper towel to gently rub off the skin. Some of it will remain, which gives the tomato a sort of rustic appearance. The slight caramelization of the skin has a pleasant and aromatic flavor. Arrange the tomatoes on a screen in another pan to allow the circulation of smoke and to protect them from direct heat. 
Remove the skin from the onion and slice into four. Arrange on the screen with the tomatoes. Smoke the onions and tomatoes @ 275 F/135 C for one hour; then, increase the heat to 400 F/204 C for one hour. 
Note: Some practitioners like to season/flavor the tomatoes and onions before smoking. This is a matter of preference. I do not recommend coating with oil. First, it accelerates the cooking process and therefore may change your results. Oil combined with acidity and heat can itself change flavor giving the end result a slightly rancid, off taste. This effect is magnified by subsequent refrigeration. Allow to cool, and refrigerate if desired. Served al fresco as a sort of antipasto, this dish is excellent eaten on the patio at room temperature over cool crisp lettuce. Drizzle with a little Maldon salt and fresh ground pepper, dress lightly, At service, arrange the Butter lettuce on the bottom of the plate, and place some tomatoes and onions on top. This can be done family style or be plated individually with equally impressive results. In the bottom right picture of the slide, I have sprinkled the tomatoes with a little Hondashi and some olive oil as garnish for my Hamburger. The flavor and texture is a great companion to any sandwich, hot or cold. 
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