Wash peppers, peas and spring onions and cut into 3 cm pieces. Peel the garlic and cut into thin slices, mushrooms into 2 cm thick slices.
Season fish fillets with salt and pepper on both sides. Heat oil in a pan and fry the fillets on skin side, turn and finish them.
Besides, fry the vegetables in another pan in hot oil and season with salt, pepper, thyme and garlic.
Arrange fish fillets on the vegetables.