Peel garlic and cut it lengthwise into smaller manageable pieces.
Peel and slice onion.
Make some holes all over the pork tenderloin and push a garlic piece into each hole until all garlic has been used up.
Season pork with salt, black pepper, and caraway seeds OR cumin (any of the two).
Place lard (or butter) with the sliced onion into a large pot and keep pork tenderloin over that.
Preheat oven to 400° Fahrenheit/ 200° Celsius.
Place a large pot over the stove to sear the meat and onions first. Brown meat on all sides.
Pour broth into the pot and mix it a bit in. Cover the pot.
Place into the oven and roast pork for about 20-30 mins at 400° Fahrenheit/ 200° Celsius altogether. The duration depends on how you want your meat cooked, if it should be pink (cook for 20 mins) or well done but juicy (cook for 30 mins). Use a thermometer to determine inner temperature doneness (see notes).
Prepare slurry by combining flour and water.
Pour after 15-20 mins cooking time the slurry into the pot and mix it in to create a thick sauce and finish cooking your meat.
Take out meat when done and pour sauce over the meat. That will bring out the lovely color of the sear. Cut into meat slices and serve up with the sauce.
Video
Notes
For medium-rare, at 145 Fahrenheit/ 60 Celsius, up to 160 Fahrenheit/ 70 Celsius Medium well-done.