Pat beef cubes dry with paper towels and season generously with salt and pepper. Working in two batches, sear meat in hot olive oil for 3-4 minutes per side until deeply browned. This step builds the savory foundation that makes this comfort beef so satisfying.

Remove beef and add diced onion to the same pot, stirring for 2-3 minutes until softened. Add minced garlic and cook for 30 seconds until fragrant, then stir in tomato paste for another minute.

Pour in beef broth, scraping up browned bits from the bottom—these flavor particles are liquid gold. Return beef to the pot and add bay leaf, thyme, and rosemary. Bring to a boil, then reduce heat to maintain a gentle simmer.

Add cubed potatoes, sliced carrots, and chopped celery. Simmer uncovered for 30 minutes, stirring occasionally, until vegetables are tender and beef shreds easily with a fork. The beef stew recipe achieves perfect tenderness at this point.

In a small bowl, whisk cornstarch and water into a smooth slurry. Stir this into the pot and simmer for 3-5 minutes until the broth thickens to silky consistency. Taste and adjust seasoning as needed.