• Preheat oven to 350℉ with racks set to the lower portion of the oven. Gather the ingredients so you have everything close at hand on the counter or table.

Prepare the Ingredients

• Using a cutting board and a sharp filet or santoku knife, slice 3 pounds venison meat (backstrap or loin) into thin strips, about 1/4" thickness. Pound the meat with a meat mallet to thin them out even more, but be careful not to tear holes in them. Place the flattened strips of venison on a large baking sheet.
• Slice 10 slices thick bacon in half.
• Using a second cutting board and a clean Santoku or Chef's knife, halve and slice 1/2 medium red onion into thin pieces. Slice 3 each celery into thin pieces. Place in a medium bowl for use later.
• Peel and dice 2 medium carrots. Dice 1 cup sweet onion. Mince 2 cloves garlic. Place with the celery for use later.
• Make a beef broth with 3 cubes beef bouillon + 3 cups water (boiling.)

Assemble the Rouladen

• For ease of assembling, have premeasured bowls of bacon pieces, 1/2 cup Dijon mustard, 20 each cornichons, and sliced red onions. You'll also want a handful of large wooden toothpicks or skewers.
• Lay a row of venison slices on a work area. If you have the space, go ahead and lay out all of the slices for ease of putting it all together. Spread the Dijon mustard over the meat. Next, place a piece of bacon lengthwise on the meat, followed by some red onion and a cornichon at the base of each strip of meat.
• Begin rolling the meat tightly, keeping everything together. Secure the end with a long toothpick or wooden skewer. Place the rolled meat on the baking sheet. Repeat with the remaining strips of venison.
• Once you have all the meat rolled, heat a large Dutch oven over medium high heat with 3 tablespoons vegetable oil. Sear the rolls of meat until the sides are nicely browned.
You'll want to cook the meat in batches of 4 or 6, being careful not to overcrowd the pan. Transfer the browned Rouladen to the baking tray and repeat until all of the rolls have been nicely seared.

Prepare the Sauce

• Add 3 tablespoons olive oil and 2 tablespoons butter to the Dutch oven and sauté the prepared onion, celery, carrots, and garlic. Cook on medium low until the vegetables are just tender, about 5 minutes. Stir occasionally with a wooden spoon or spurtle.
• Season with 1/2 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper. Create a hole in the center of the pot and add 3 tablespoons tomato paste. Cook and stir into the vegetables.
• Pour in 1 1/2 cups red wine and scrape all the browned bits from the bottom of the pan.
• Nestle the browned Rouladen into the pot in layers. Pour the prepared beef bouillon over the meat until it almost covers the meat. Add in 2 small bay leaves. Cover the Dutch oven and place in the preheated oven on one of the lower racks. Bake for 1 1/2 - 2 hours.
• After the allotted baking time, check the venison for tenderness. If needed, continue baking in covered Dutch oven for an additional 20-30 minutes until the meat is fork tender.

Finishing Steps

• Once the Rouladen are quite tender, carefully transfer the meat rolls to a platter. Pick out the bay leaves from the sauce and discard. If desired, strain the vegetables for serving on the side.
I usually leave the vegetables in the pot and blend them into the liquid with an immersion blender. If you want a more traditional gravy, then simply strain the vegetables from the pot and continue on with the instructions.
• Prepare a thickener by whisking together 1/3 cup all-purpose flour + 1/3 cup water to make a thin paste. Whisk into the sauce and cook on medium-low heat until it thickens.
• Season with 1/2 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper as desired. Add 2 tablespoons butter and stir until incorporated.
• Carefully remove the toothpicks or wooden skewers from the meat and return the Rouladen back to the Dutch oven, coating them evenly with the thickened sauce. Simmer for a few minutes until heated through.
• Serve the Rouladen and Sauce with mashed potatoes or German Spaetzle. Serves 8-10.