For the sherry-bacon vinaigrette:
(Makes 1 cup)
1/3 cup sherry vinegar
1 Tbs. Dijon mustard
1 Tbs. finely diced shallot
1½ tsp. minced garlic
1 Tbs. thyme leaves
4 Tbs. warm bacon fat, preferably from Benton’s bacon
1/2 cup canola oil
Kosher salt and black pepper
Put the vinegar, mustard, shallot, garlic, and thyme in a blender and blend on low speed. With the blender running, slowly stream in the bacon fat and the canola oil to emulsify the vinaigrette. Season with salt and pepper to taste.
For the tempura:
1 cup cake flour, divided (substitute rice flour if you desire a gluten-free product)
1/2 cup cornstarch
1/4 tsp. kosher salt
1 egg, lightly beaten
1 cup ice-cold soda water plus extra if needed to thin the batter
1 lb. small green beans, washed and trimmed
Chef’s Note: There are three key points to a light and crispy tempura: mix the batter just prior to using it; keep the batter as cold as possible; and only fry a few pieces at a time—a crowded fryer produces a soggy product.
Fill a deep pot with three inches of oil (or countertop deep fryer with the recommended level of oil) and preheat it to 350°F.
Line a baking sheet with paper towels.
Put 1/2 cup of the flour, the cornstarch, salt, and egg in a mixing bowl. Add the ice-cold soda water and stir until just combined. Your mixture should be slightly lumpy.
Put the remaining 1/2 cup of flour in a pie plate. Dredge six green beans in it. Then, one at a time, drag them through the batter to lightly coat and place in the hot oil. Each batch will take around a minute to cook. You want an even golden color.
Remove the beans from the oil and place them on the paper towel-lined baking sheet to drain. Repeat until all of the green beans have been fried. (If the batter begins to thicken after a few batches, add an additional splash of ice-cold soda water to return it to the correct consistency.)
Drizzle the sherry-bacon vinaigrette over the tempura green beans or put it in a bowl for dipping. Unused vinaigrette can be refrigerated in a tightly closed container for up to two weeks.