Kung Pao Cauliflower Vegan

Name: Kung Pao Cauliflower (Vegan)
Ingredients: 2 tablespoons vegetable oil, divided; 1 medium head of cauliflower, cut into florets; 1 green bell pepper, cut into thin strips; 1 red bell pepper, cut into thin strips; 1 large shallot, thinly sliced; 2 cloves garlic, minced; 4 scallions, chopped; ¼ cup chopped peanuts; Salt and pepper, to taste For the sauce; ⅓ cup low-sodium soy sauce; 1 tablespoon rice vinegar; 1 tablespoon sambal oelek; 1 tablespoon sesame oil; 2 tablespoons brown sugar; ½ teaspoon ground Sichuan pepper; 2 teaspoons grated fresh ginger; ¼ cup vegetable stock; 3 teaspoons cornstarch