Oven Method: Preheat the oven to 375°F (190°C). Arrange the fresh kielbasa in a single layer in a baking dish or on a rimmed baking sheet. Add 1 cup water. Cover with foil and bake for 30 minutes. Remove the foil and continue baking for 15–20 minutes, until browned and cooked through. The internal temperature should reach 160°F (71°C).

Stovetop Method: Heat 1 tablespoon vegetable oil in a large skillet over medium heat. Add the fresh kielbasa and 1 cup water. Cover and cook for about 15 minutes, turning occasionally. Remove the lid and continue cooking for 5–10 minutes until browned. The internal temperature should reach 160°F (71°C).

Boiling Method: Place the fresh kielbasa in a large pot and add enough water to cover it. Bring the water to a gentle simmer and cook for 20–25 minutes. Check that the thickest portion reaches 160°F (71°C), then remove and serve.