In wok or large skillet with cover, heat olive oil over high heat until nearly smoking. Stir fry garlic, shallots and chicken. Remove to a bowl. Add leeks to wok and stir fry 3 minutes. Remove to chicken bowl. Add potatoes, carrots, lemon peel and tarragon and stir fry 5 minutes. Return chicken and leeks to wok. Add 1/2 cup water, stir quickly, cover tightly and steam 5 minutes. Add more water if necessary. Remove from heat, add cheese and, if desired, peas. Stir and serve. Serve with a green salad and light sourdough French bread or crusty rolls.