Stir-Fried Cabbage
["1 1/2 lb. green cabbage, finely shredded", "1 handful finely chopped celery leaves", "3 scallions, including green stems, cut into 3-inch lengths and then cut lengthwise into thin strips", "3/4 tsp. salt or to taste (preferably kosher salt)", "5 Tbsp. oil", "4 cloves garlic", "6 shallots or 1 large onion", "3 Tbsp. water", "1/4 c. olive oil", "2 Tbsp. butter", "1 lb. onions, sliced 1/8-inch thick", "2 lb. red peppers in strips", "2 lb. tomatoes, peeled, seeded and coarsely chopped", "3 tsp. red wine vinegar or to taste", "1 tsp. salt", "black pepper to taste"]
["In heavy 12-inch skillet, melt 2 tablespoons of butter and 1/4 cup oil over moderate heat.", "Add onions and cook, turning frequently, for 10 minutes or until they are soft and lightly browned.", "Stir in peppers; reduce heat, cover and cook 10 minutes. Add tomatoes, vinegar, salt and pepper. Cover and cook 5 minutes. Cook vegetables, uncovered, over high heat, stirring gently, until most of liquid has boiled away.", "Reseason.", "Serve at room temperature."]
["green cabbage", "handful", "scallions", "salt", "oil", "garlic", "shallots", "water", "olive oil", "butter", "onions", "red peppers", "tomatoes", "red wine vinegar", "salt", "black pepper"]