Clean, wash and drain the sugar snap peas. Wash tarragon, shake dry and pluck off the leaves. Put rice into 400 ml boiling salted water and let it swell covered for about 20 minutes.
Wash the chicken fillets and pat them dry. Heat the oil in a pan and fry the fillets for about 4 minutes, turning them until golden brown. Season with salt and pepper, pour on stock and cream and add the tarragon.
Simmer without lid for 6-8 minutes. In the meantime, put frozen peas in 250 ml salted water, cover and bring to the boil over a high heat. Add sugar snap peas, bring to the boil again and simmer covered over medium heat for 3-4 minutes.
Stir mustard into the tarragon cream sauce and season with salt and pepper. Drain the sugar snap peas and peas on a sieve and add to the chicken fillets in the pan. Add the rice.