Here's a recipe for homemade butter and Mayonnaise (both a saturated fat)
Mayonnaise
1 egg yolk
1/4 tsp Dijon mustard
2 tsp lemon juice
Dash worcestershire
Pinch of sugar
Salt and Pepper to taste
1/2 C oil
In a small bowl, add egg yolk, Dijon mustard, lemon juice, a dash of Worcestershire, and pinch of sugar. Using hand blender mix until combined. Using the liquid measuring cup, VERY SLOWLY, drizzle in the oil to the bowl with egg mixture while your hand blender is on high. It should be a slow drip you are streaming in the bowl (a stream the size of yarn). Mix until all of the oil has been poured in (about 10 minutes). Add salt and pepper to taste
Butter
2 cups heavy cream
1/2 tsp salt
Beat on high with hand blender until mixture resembles
large curds of cottage cheese and starts becoming sold. Using a spatula (or cheese cloth),
squeeze out the butter milk (this is drinkable if you’d like to taste) and
season with salt and pepper to taste. Refrigerate
immediately unless you are serving.