Prep the beef lean and small: Trim all visible fat. Cut into 1/2-inch cubes so they dehydrate and rehydrate quickly. Pat dry with paper towels for better browning.
Sear for flavor: Heat a pot over medium-high.
Add a light film of oil. Brown the beef in batches without crowding. Season with salt and pepper.
Remove to a plate.
Build the base: In the same pot, add onions, carrots, and celery. Sauté 5–6 minutes until softened and lightly browned. Stir in garlic and tomato paste for 1 minute.
Simmer the stew: Return beef to pot.
Add broth, herbs, smoked paprika, and bay leaves. Bring to a gentle simmer and cook 30–40 minutes until beef is tender.
Add potatoes and quick-cook veg: Stir in potatoes (and mushrooms, if using). Simmer 12–15 minutes until just tender.
Add peas in the last 3 minutes. Remove bay leaves.
Thicken slightly: Stir in the cornstarch slurry and simmer 2–3 minutes until the stew is lightly thickened. Do not make it gluey; a light body helps it dry evenly.
Cool completely: Spread the stew in shallow pans to cool quickly to room temp, then refrigerate until chilled. Cold stew dehydrates more evenly and safely.
Dehydrate: Spread the stew in thin, even layers (no more than 1/4 inch) on dehydrator trays lined with solid sheets. Set to 145–155°F (63–68°C).
Dry 8–12 hours, rotating trays as needed, until the stew is dry, brittle, and no pockets of moisture remain. Beef should be hard and veggies crisp.
Optional oven method: Use parchment-lined sheet pans at the lowest oven setting (ideally 170°F/77°C) with the door cracked slightly. Stir occasionally.
Times vary; watch closely to avoid scorching.
Condition the batch: Once fully dry and cooled, place the dried stew in a large jar or bag for 24 hours at room temp, shaking once or twice. If condensation appears, return to the dehydrator.
Portion and pack: Divide into single servings of about 1 to 1.5 cups dried mix (roughly 120–180 g). Label with date and rehydration instructions: “Add boiling water 1:1.25 to 1:1.5 by volume, soak 10–15 min.” Vacuum seal for longest shelf life.