If you’re looking for a comforting, flavorful meal to make for your next cozy dinner, this French Onion London Broil is the perfect option! Slow-cooked beef, caramelized onions, and juicy cherry tomatoes come together with toasted bread and melty cheese for a dish that’s rich, hearty, and irresistibly delicious.
I am a HUGE fan of French onion soup, so this recipe was born from my love of those flavors paired with the heartiness of a slow-cooked London broil and the acidity of tomatoes. There’s something about the richness of caramelized onions and the savory broth that’s so comforting. Plus, adding that cheesy bread on top is a must! It’s an all-in-one dish that hits all the right notes, making it ideal for a weekend dinner or when you’re craving something extra special.
To make it a full dinner, I serve this beef and French onion soup over potatoes, such as my Air-Fryer Baked Potato. It was complete without the classic crispy bread and melty cheeses.
Why This Recipe Works
- Rich, caramelized onions: Slow-cooked to perfection, these onions create a sweet, savory base that adds depth to the beef.
- Slow cooking makes the meat tender: London broil can sometimes be tough, but this cooking method ensures the beef comes out perfectly tender and flavorful.
- Toasted cheesy bread: Adding slices of toasted bread topped with broiled cheese takes the dish to the next level, giving you a crunchy, gooey element to enjoy alongside the beef.
- Easy slow cooker meal: While it starts on the stove, everything is finished in the slow cooker, so it’s low-maintenance after the initial steps.
Ingredients for Beef and French Onion Soup Recipe
This recipe has a few simple ingredients and is full of rich, deep beefy flavor and the best onion soup made in the slow cooker.
London broil – A lean cut of beef that becomes tender when slow-cooked.
Onions – The star ingredient for that classic French onion flavor. I like to use sweet onions or red onions, depending on the flavor I’m going for.
Cherry tomatoes – Adds a pop of color, acidity, and juiciness to balance the richness.
Beef broth – Adds a rich, savory base to the dish.
Butter and olive oil – The butter helps with browning, while the oil prevents burning
Bay leaf – A subtle herb that enhances the overall flavor during the slow cooking process.
Thyme – A classic herb that complements the beef and onions.
Dry red wine – Used to deglaze the pan and capture all those flavorful bits.
Sugar – Helps the onions caramelize and brings out their natural sweetness.
Garlic – Adds an aromatic, savory depth to the onions.
Bread – Baguette or sourdough works great for holding all that gooey cheese and soaking up the broth.
Cheese of choice
How to make French Onion Soup with Beef
Prepare the slow cooker: Add the broth and bay leaves, then set to high.
Sear the London broil: Season the beef and sear it in butter and olive oil until browned on all sides.
Caramelize the onions: Cook the onions low and slow with butter and sugar until deeply caramelized. Add garlic near the end.
Deglaze with wine: Use the wine to scrape up all the browned bits from the skillet, then pour the onions and wine mixture over the London broil in the slow cooker.
Slow cook: Add the tomatoes and thyme to the slow cooker. Cook on high for 3-4 hours (or low for 6-7 hours) until the beef is tender.
Toast the bread & broil the cheese: Toast slices of bread, then top with shredded cheese and broil until bubbly.
Serve: Slice the beef, spoon over the caramelized onion sauce, and serve with cheesy toast on the side.
Helpful Recipe Tips
- Take your time with the onions: The key to the best flavor is in the slow caramelization of the onions. Don’t rush this step!
- Deglaze thoroughly: Scraping up all the flavorful bits from the pan after searing the beef and caramelizing the onions adds an extra layer of flavor to the broth.
- Adjust for tenderness: If your London broil isn’t as tender as you’d like after the recommended time, leave it in the slow cooker for an additional 30-60 minutes.
Frequently Asked Questions
Yes, you can make this French onion soup with london broil in a large pot or Dutch oven on the stove. First, sear the beef on all sides and then set it aside. Follow the steps for cooking the onions and making the recipe. Then simply add the beef and tomatoes to the pot instead of a slow cooker and simmer covered on the stove until the beef is tender, about 2-3 hours.
Yes, and no. You could go either way with this recipe for London broil slow-cooked in French onion soup. I have served it both thickened into a gravy and as a soup. So, French onion gravy with London broil and potatoes supper, or French Onion and Beef Soup.
Yes! If you can’t find London broil, chuck roast or top round would work well as alternatives for this recipe.
Leftover beef and sauce can be stored in an airtight container in the fridge for up to 3 days. They can be reheated on the stovetop or in the microwave. When ready to eat, the cheesy bread is best toasted and broil fresh.
If you prefer to skip the wine, you can deglaze the pan with extra beef broth or even a splash of balsamic vinegar for a different kind of richness.
More Dinner Recipes
- Spicy Slow Cooker Chili
- Lentil Beef Stuffed Peppers
- Vegetable Beef Soup
- One-Pot Rustic Beef Tortellini Stew
- Braised Beef Short Ribs
This French Onion London Broil recipe is the ultimate comfort food, blending the classic flavors of French onion soup with the heartiness of slow-cooked beef. The caramelized onions, tender meat, and cheesy bread create a dish that’s perfect for chilly evenings or when you just need a little extra coziness in your life. Whether you’re feeding your family or hosting guests, this recipe is a guaranteed hit!
Serve with some mashed potatoes or roasted veggies for a complete, satisfying meal that everyone will love.
Let me know in the comments if you tried this recipe. Be sure to tag @ladleandgrain on Facebook and Instagram!
French Onion London Broil
Course: All Recipes, soups, dinner, mainCuisine: American, French8
servings30
minutes8
hoursIngredients
4 cups beef broth
2 bay leaves
1 teaspoon red pepper flakes
2 pounds London Broil
2 teaspoons salt
1/2 teaspoon black pepper
1 tablespoons olive oil
2 tablespoons unsalted butter, for searing
1/2 cup butter, for caramelizing onions
6 large onions, sliced
1 tablespoon sugar
4 garlic cloves, minced
1/2 cup dry red wine
1 pint cherry tomatoes
2 teaspoons dried thyme
Crusty bread, for serving
Sliced or shredded cheese for serving
Directions
- Turn the slow cooker to high. Add 4 cups of beef bone broth, bay leaves, and red pepper flakes.
- Heat a large skillet over medium-high heat. Season the London broil with salt and pepper. Add 2 tablespoons of butter and 1 tablespoon of olive oil to the skillet. Once melted, sear the London broil on all sides until golden brown, about 2-3 minutes per side. Transfer the seared beef to the slow cooker and cover.
- Reduce the heat to medium. Add the remaining butter to the skillet. Once melted, stir in the sliced onions and sugar. Cook for about 25 minutes, stirring occasionally, until the onions are soft and caramelized. In the last 8 minutes, add the minced garlic and cook until fragrant.
- Pour the red wine into the skillet to deglaze, scraping up the brown bits from the bottom with a wooden spoon. Let the wine reduce for 1-2 minutes. Pour the onion mixture over the London broil in the slow cooker.
- Add the cherry tomatoes and thyme into the broth around the beef.
- Cover and cook on high for 3-4 hours or on low for 6-7 hours, until the London broil is tender.
- About 10 minutes before serving, preheat your broiler. Arrange slices of bread on a baking sheet and toast under the broiler for 1-2 minutes on each side, or until golden and crisp. Then, top with cheese and continue broiling until the cheese is melted and bubbly.
- Slice or shred the London broil and serve with the rich onion and tomato soup with 1-2 pieces of cheese bread on top.
