Melt butter over low heat in a saucepan with olive oil.
30 g burro vegano, 1 cucchiaio di olio extravergine d'oliva
Add the onions and sauté them (again over low heat) until softened.
1 cipolla bianca tritata finemente
Add the flour and ladle it into the butter. Then add the broth, continuing to stir for 3-4 min.
1,5 cucchiai di farina, 250-300 ml di brodo vegetale
Add the soy sauce and cook for another 2-3 minutes.
2 cucchiai di salsa di soia, q.b sale e pepe