Heat a little oil in a large frying pan or skillet on a medium high heat.

Remove sausage meat from the casings and crumble into the pan. Discard casings.

Cook for 3-5 minutes, stirring to break up the chunks, until the meat is starting to brown.

Add tomatoes and butter and cook for another 10 minutes for the sauce to reduce a little.

Serve on a bed of baby spinach.