I get mine from a the same rancher I get my beef fat (for tallow) from. Met her at a local farmer's market. I prefer the pancreas to the thymus, but the thymus ain't bad! Both are high in Vitamin C, gorgeous fat and protein. I trim the dangly bits. Poach in salt water for 20 minutes. Stack between a few plates with a stone on top to flatten for a few hours in the fridge. Slice into half inch cutlets. Salt (and pepper, if desired) Saute in bacon fat until golden on both sides. The pancreas especially has a buttery, almost scallop like, consistency.