Bearnaise Sauce

1. Preheat oven to 300 degrees F. Place tomatoes onto baking sheet and drizzle each with olive oil, turning to coat. Place in oven and roast for 30 minutes. Turn and roast an additional 10 minutes.
2. Transfer tomatoes to a blender and blend until smooth.
3. While motor is running slowly add 1/4 cup olive oil until emulsified, taking turns with adding vinegar, mustard, salt, and pepper. Pour sauce through a fine mesh sieve into a bowl and set aside.
4. Heat 1 tablespoon olive oil in a large skillet over medium heat, saute shallot for about 2 minutes. Add tarragon and saute stirring often so shallots don't pass golden brown. Add wine and cook until liquid is reduced by half, about 5 minutes.
5. Add the tomato mixture; bring to a simmer then turn off heat. If sauce is too thin, add a mixture of arrowroot powder mixed with 1/4 cup water. Whisk in vegan margarine, 1 tablespoon at a time. Use immediately or cover to keep warm.
Source of recipe: A compilation of a couple put together.