Pan-fried bread dumplings with mushroom vegetable cream sauce

Name: Pan-fried bread dumplings with mushroom vegetable cream sauce
Cuisine: European, British
Ingredients: 450g dry white bread cubes / stale rolls or bread, cubed (or diced); 700ml plant-based milk; 2 tsp salt; 4 tbsp plant-based yogurt; 2 onions; some olive oil; 20g plant-based butter; 5 tbsp olive oil; 2 onions; 5 tbsp olive oil; 500g mushrooms; 2 yellow bell peppers (ca. 370g); 3 carrots (ca. 230g); 300g plant-based sour creme (or plant-based (heavy) cream for cooking); 15g parsley (fresh or from the freezer); 2 ½ tsp salt; 1 tsp pepper