Make Giblet Broth: In a large saucepan, place all of the giblets and add enough water to ensure they are fully covered. Cover and bring to a low simmer over medium heat. Let cook for 2-4 hours (add additional water, as needed). Remove giblets and set aside so you are left with the giblet broth. 

Make Gravy: In a deep skillet or medium saucepan, melt butter on medium-high heat. Once butter is melted, add in flour and whisk to combine. This will create a sort of paste (called a roux) and it should have an almost nutty smell. Slowly add in 3 cups giblet broth, whisking constantly. Continue to slowly pour in the giblet broth, whisking the whole time, until it is all added. 

Taste & Consistency: Taste the gravy and add any salt or pepper, if needed. Assess the consistency of the gravy - if you like it a little thinner, add broth a little at a time, whisking to combine, until you have reached your desired consistency. If you want a thicker gravy, let it simmer (a soft boil) for a bit and it will continue to thicken.

Serve: enjoy this classic giblet gravy immediately with Instant Pot mashed potatoes and your favorite Giblet Stuffing.