Pat the beef cubes dry with paper towels. In a bowl, toss the beef with 2 tsp kosher salt, 1 tsp freshly ground black pepper and 3 tbs flour until evenly coated. Shake off excess flour.

Brown the beef

Heat a large heavy-bottomed pot or Dutch oven over medium-high heat. Add 4 tbs vegetable oil. In batches (do not crowd the pan), add the beef and sear until deeply browned on all sides, about 3–4 minutes per batch. Transfer browned beef to a plate and set aside.

Aromatics and mirepoix

Reduce heat to medium. If the pot is dry, add 1 tbs oil. Add diced onion, carrot and celery. Cook, stirring occasionally, until softened and beginning to brown, about 6–8 minutes. Add the minced garlic and cook 30–60 seconds until fragrant. Scrape up any browned bits from the bottom of the pot (deglaze).

Tomato and bell pepper sauce

Add the diced red bell pepper to the pot and cook 3–4 minutes to soften. Stir in 3 tbs tomato paste and cook 1–2 minutes to remove raw flavor.

Pour in 1 cup red wine (if using) to deglaze, scraping up browned bits; simmer 2 minutes to reduce slightly. Add the canned diced tomatoes (including juices), 3 cups beef stock, 1 tsp smoked paprika, 1 tsp dried thyme, 1 tsp Worcestershire sauce and 1 bay leaf. Stir to combine.

Return the browned beef and any accumulated juices to the pot. Bring the mixture to a gentle simmer, then reduce heat to low. Cover partially and simmer gently for 45 minutes.

Finishing and garnish

After 45 minutes of simmering, add the 2 cups cubed potatoes to the stew. Continue to simmer, uncovered or partially covered, until the potatoes are tender and the beef is fork-tender, about 20–30 more minutes. Check occasionally and skim excess fat if needed.

Taste the stew and adjust seasoning with salt and pepper to taste. Stir in 1 tbs butter for a glossy finish and 2 tbs chopped fresh parsley.

Remove and discard the bay leaf. Spoon the stew into bowls and serve hot with crusty bread or over mashed potatoes.