Core the tomatoes, cut into pieces, and place in a blender. Blend until pureed. Strain through a sieve into a bowl. You should have about 2 1/2 cups puree. If fresh tomatoes are not available use canned.
Heat 1 tablespoon of the olive oil in a non-reactive medium saucepan until hot. Add the garlic and saute briefly until light brown. Add the tomato puree and bring to a boil. Simmer gently about 5 minutes. Strain through a fine-mesh sieve into a bowl. Discard the solids. Rinse out the saucepan, return the tomato juice to the pan, and bring to a boil. Simmer and strain twice more until the tomato juice is as thick as heavy cream, about 15 minutes total cooking time. Be sure to lower the heat as the mixture thickens to prevent scorching. You should have about 1/4 cup of very smooth tomato juice. Add 1 tablespoon lemon juice and taste for salt and pepper.
Pour 1 tablespoon of the olive oil into a small, clean glass bottle with a stopper and swirl to coat the inside. Coat the glass bottle with olive oil and the funnel before straining tomatoes so they don't stick. Strain the tomato juice into the bottle. Let it cool to room temperature. Add olive oil - mixture should be half olive oil and half tomato. Do not shake or mix!
Bring a large pot of water to a boil and add salt. Blanche the corn and cook just until tender, about 3 minutes. Remove and set aside. Cook the beans in the same water just until tender, about 3 minutes. Drain. If using favas, peel them. When the corn is cool enough to handle, cut the kernels from the cobs. Toss together in a bowl.
Season the fish on both sides with salt and pepper. Heat 2 tablespoons olive oil in a large saute pan over medium-high heat until hot. Put presentation side of the fish (non-skin side) in pan first as it gets the best caramelization. Cook until brown on the first side, about 3 minutes. When you see it getting opague around the edges, give it another minute and flip sides. Cook another minute on other side. Remove from pan and place on cookie sheet for a bit while you enjoy your appetizer with company. Just before you're ready to serve it, put it in a preheated 450 degree F oven for about 30 seconds.
In a clean jar with a lid, shake together minced tarragon, 2 tablespoons of the bacon, and 25 percent of Champagne vinegar and 75 percent olive oil. Pour enough of the dressing onto the corn and beans to coat, toss well, and taste for seasoning. Adjust with salt, pepper, and more dressing as necessary. Set aside to marinate for about 15 minutes.