Beef tendon/sinew—the fibrous parts of beef used in stewed dishes (e.g., oden), rich in collagen and softened by long cooking.
居酒屋で牛すじ煮込みを注文したら、とても柔らかく煮えていた。
I ordered stewed beef tendon at the izakaya, and it was cooked very tender.
寒い日に牛すじと大根を一緒に煮るとよく味が染みる。
If you simmer beef tendon with daikon on a cold day, the flavors soak in well.
スーパーで安く売っていた牛すじを買って、味噌煮にした。
I bought beef tendon cheaply at the supermarket and made a miso stew.