Possible Clues:

• Tough meat
• Bit of roast leg, it's thrown out
• Cartilage: it's leg doctor finally sorted out
• Hard-to-chew piece of meat
• Cook -- no learner -- set grill for rubbery piece of meat
• Inedible cartilage
• Let's rig what's tough to meet, by the sound of it
• Ultimately ruining dinner, fibre and cartilage
• Miller's material extremely low-grade? That's hard to swallow
• The seaman is in the drink