Note: There are two recipes here - the first is the filet of beef, the second is the basil Parmesan mayonnaise. You'll have plenty of time to prepare the mayonnaise while the beef is roasting... plus is stays good for about a week in the refrigerator.
Slow-Roasted Filet of Beef
by Ina Garten
1 whole filet of beef tenderloin, trimmed and tied (4 1/2 pounds)
3 tablespoons good olive oil
4 teaspoons kosher salt
2 teaspoons coarsely ground black pepper
10 to 15 branches fresh tarragon
Basil Parmesan Mayonnaise, for serving (see recipe below)
1. Preheat oven to 275 degrees F. Use an oven thermometer to be sure your oven temperature is accurate.
2. Place the filet on a sheet pan and pat it dry with a paper towel.
3. Brush the filet all over with oil, reserving about a half a tablespoon.
4. Sprinkle it all over with the salt and pepper - it will seem like a lot but it makes a difference.
5. Place tarragon branches around the beef, tying them in 4 or 5 places with kitchen string to them in place and then brush the tarragon with the reserved oil.
6. Roast the filet of beef for 1 1/4 to 1 1/2 hours, until the temperature registers 125 degrees in the center for rare and 135 degrees for medium-rare.
7. Remove and cover the filet of beef with aluminum foil and allow to rest for 20 minutes.
8. Slice thickly and serve warm or at room temperature with the Basil Parmesan Mayonnaise.
Basil Parmesan Mayonnaise
2 extra-large egg yolks, at room temperature
3 tablespoons freshly squeezed lemon juice
1/2 cup freshly grated Parmesan cheese
1 tablespoon Dijon mustard
1/2 cup chopped fresh basil leaves, lightly packed
1/2 teaspoon minced garlic
kosher salt and freshly ground pepper
1 cup vegetable oil
1/2 cup good olive oil, at room temperature
Place the egg yolks, lemon juice, Parmesan cheese, mustard, basil garlic 1 tablespoon of salt, and 1 tablespoon of pepper in a food processor fitted with the steel blade. Process for 20 seconds, until smooth. Combine the vegetable oil and olive oil in a 2-cup liquid measuring cup. With the processor running, slowly pour the oil mixture through the feed tube to make a thick emulsion. Taste for seasoning - the mayonnaise is a sauce so it should be highly seasoned. Store in the refrigerator until ready to use; it will keep for up to a week