I don't have any recipes, but I actually do make this pretty often. I use a two-pan method because it makes a cleaner-looking gravy - most recipes recommend using the same pan, but that always results in a muddy-looking sauce for me (it tastes great, but just doesn't look as good).
1. Brown some crumbled sausage in a pan, then pour it through a strainer. Set aside both the sausage and the strained oil. You can also deglaze the pan and add the crunchy brown bits back at the end if you wish, but I usually don't.
2. In a separate pan, make a roux with a tablespoon of butter & flour on low heat (or some combination of butter & the strained oil. I typically use just butter, as the oil tends to create a 'dirty' gravy).
3. When the roux is mixed well and just starting to darken, pour in about 1/2 cup of milk, and turn the heat up to medium low to medium, and start stirring.
4. Keep stirring until it starts to bubble and thicken, then turn it back down to low.
5. Add the crumbled sausage back in, plus a bit of the strained oil. Keep stirring.
6. Add salt & pepper to taste. I purposely wait until now to add this, because the sausage will make it hot & salty by itself, so it's very easy to overdo it if you season beforehand.
7. Keep stirring on low heat until it reaches the desired consistency.
I like serving it on tater tots.
"I've always thought pastrami was the most sensuous of the salted cured meats."