Stir-Fried Cabbage - cooking recipe

Ingredients

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

Preparation

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.