Place meat in dutch oven. Just cover with water. Add celery and onion. Cover and bring to a boil. When meat boils, turn down to heat to medium low and cook for 1 - 2 hours until internal temp of Beef reaches about 145°F / 113°C, or until tender. Venison should be cooked until about 150° F / 115 ° C. Let meat cool in broth. I usually let the meat cool until cool enough to rest in the refrigerator overnight.
Cook potatoes in a small saucepan in boiling, salted water until tender but not mushy. About 20 minutes. Drain and cool. Grate cold potatoes with a coarse grater.
Heat 1 Tbsp. olive oil in a large, heavy bottom skillet. Remove Chorizo from casing. Brown Chorizo in batches (do not overcrowd pan) and break apart as it browns. After all the chorizo has browned, turn down heat and add onion and cook until onion is tender, stirring occasionally.
Meanwhile, Shred meat, traditionally beef is cut across the grain into 1 1/2" long pieces and shredded with 2 forks. This makes a large batch, so it would take forever to shred so I pulse in a food processor a few times. Don't over process.
Heat about 2 Tbsp. olive oil over medium heat, to the the pan with chorizo and onion. Add shredded meat, potatoes, tomato sauce and salt and pepper to taste. Stir constantly for about 3 minutes, just until heated through.
Wrap about 6 tortillas in Damp paper towel and place on microwave safe plate. Cover plate with plastic wrap and microwave about 30 seconds until softened. Place about 1 tablespoon of Steak and Chorizo filling in a narrow strip at one end of tortilla. Roll up tightly. Place on cooling rack, seam side down. Pour oil into a small skillet about 1/2" deep. Heat to 365°F / 185°C. Carefully place seam side down in hot oil. Fry several taquitos at a time until crisp. Drain over skillet and then on paper towels.
Taquitos can be frozen for several months before frying. Thaw thoroughly. Fry as you normally would. Filling can also be frozen for several months. Thaw filling and then fill as you would normally and then fry.
Serve with Guacamole, Frijoles (Refried beans), and salsa of your choice. Our favorite is Peach Salsa.