Name: The Back Abbey Of St. Bernardus The Tenderloin Recipe
Cook time: 1 h
Total time: 1 h
Yield: 4 servings
Cuisine: French
Ingredients: 1 lb beef tenderloin (center-cut whole or tail portion), trimmed; 2 tbs olive oil; 2 cloves garlic cloves, minced; 1 tsp fresh thyme leaves, chopped (or 1 tsp dried thyme); 1 tsp kosher salt; 1 tsp black pepper, freshly ground; 2 cups yellow onions, thinly sliced; 2 tbs unsalted butter; 1 tbs olive oil; 1 tsp kosher salt; 1 tsp granulated sugar; 1 tsp balsamic vinegar (optional, for deglaze and sweetness); 3 oz St. Agur blue cheese; 1 cup crème fraîche (or full-fat sour cream if unavailable); 1 tsp lemon juice; 0 to taste black pepper, to taste; 4 each French rolls (soft, about 6–8 inch), halved; 2 tbs unsalted butter, softened (for toasting rolls); 1 tbs fresh parsley or chives, chopped (optional garnish)

Method

Beef & Marinade

Trim and season

Pat the tenderloin dry with paper towels. In a small bowl combine 2 tbs olive oil, minced garlic, chopped thyme, 1 tsp kosher salt and 1 tsp freshly ground black pepper. Rub the mixture all over the tenderloin, coating evenly. Let rest at room temperature for 20–30 minutes (or refrigerate up to 2 hours and bring back to room temp 30 minutes before grilling).

Grill (or pan-sear) the tenderloin

Preheat a grill to medium-high (about 400°F / 200°C) or heat a heavy skillet over medium-high heat. Sear the tenderloin on all sides 2–3 minutes per side until well-browned. Move to indirect heat on the grill, or reduce pan heat and transfer to a 400°F oven if using an oven-safe skillet. Cook until an instant-read thermometer inserted into the center reads 125°F for medium-rare (about 10–20 minutes depending on thickness). Remove the tenderloin to a cutting board and tent loosely with foil; rest 10 minutes. Internal temp will rise ~5°F during resting.

Slice

After resting, slice the tenderloin into 1/2-inch thick medallions. Keep warm while finishing other components.

Caramelized Onions

While the tenderloin marinates or rests, melt 2 tbs butter with 1 tbs olive oil in a large skillet over medium-low heat. Add the thinly sliced onions and 1 tsp kosher salt; stir to coat. Cook slowly, stirring occasionally, for 20–30 minutes until the onions are deeply golden and soft. If onions begin to stick, add 1–2 tbs water to deglaze and continue cooking.

When onions are nearly done and have a rich brown color, sprinkle 1 tsp granulated sugar and 1 tsp balsamic vinegar over them, stir, and cook another 1–2 minutes to caramelize and intensify flavor. Remove from heat and keep warm.

St. Agur Crème Fraîche Spread

Crumble 3 oz St. Agur into a bowl. Add 1 cup crème fraîche and 1 tsp lemon juice. Using a fork or small whisk, blend until mostly smooth but still slightly textured. Taste and season with freshly ground black pepper to taste. If you prefer a looser spread, add 1–2 tbs more crème fraîche.

Chill briefly (10–15 minutes) if time allows so the flavors meld; bring back to room temperature before assembling if chilled.

Rolls & Finish

While onions caramelize and the tenderloin rests, split the French rolls and spread softened butter on the cut sides. Toast them cut-side down on the grill or in a skillet over medium heat until golden and crisp, about 2–3 minutes.

Assemble the sandwiches: Spread about 2–3 tbs of the St. Agur crème fraîche on each bottom roll. Top with 3–4 slices of the sliced tenderloin per roll (adjust for roll size). Spoon a generous portion (about 1/4 to 1/3 cup) of caramelized onions over the beef. Sprinkle with chopped parsley or chives if using. Cap with the top roll.

Serve immediately while warm. Leftover tenderloin slices can be refrigerated up to 3 days; store the spread and onions separately.