Meanwhile, whisk the agave, soy sauce, tomato paste, sherry, and remaining vinegar in a small bowl.
Place the pork in a single layer between two sheets of waxed paper and pound with the side of a meat mallet until thin (about ⅛-inch thick). Cut each in half lengthwise and put in a bowl with 2 tbsp of rice vinegar. Let marinate, covered, in the fridge for 20 minutes.
Remove the pork from the vinegar, shake off any excess liquid, and transfer the pieces to a clean medium bowl. Add the cornstarch and toss until coated evenly.
Place a large nonstick wok over high heat. When hot, lightly spray it with olive oil and add the scallions, bell pepper, chilies, garlic, and bamboo shoots. Cook, stirring frequently, for 3 to 5 minutes, or until the veggies just start to become tender. Remove from the pan and cover to keep warm.
Return the wok to the heat, add 1 tsp of the avocado oil and half of the pork in a single layer. Cook briefly, stirring frequently, until the pork is just barely pink inside. Add it to the veggie mixture. Repeat with the remaining oil and pork.
Dump the pork and veggies back into the wok and pour the sauce over the top. Turn off the heat. Stir until the sauce thickens slightly, enough to coat the meat and veggies.