Add olive oil to the pan and heat. Add celery, onion, and carrot. Salt and pepper to taste and saute until soft (10 minutes)

Next add the chicken stock, crushed tomatoes, and chicken powder. Bring to a boil

Using a hand blender or regular blender, blend the mixture until fairly smooth.

In a separate pan, brown the ground pork until no longer pink. When finished, add it to the sauce mixture. Put the sauce mixture on low heat while making the patties (make sure to stir occasionally)

Season the two types of meat and mix the ground pork and beef together well

Shape into patties and cook the patties in the pan to your desired doneness

Lightly toast the burger buns and then place the patty directly from the pan onto the bun.

Top with kewpie mayo, onions, and then 2 tbsps or so of the meat sauce. Finish it off with the thickly sliced tomato!