Bethine Church's Idaho dinner menu last week, which featured sugar snap peas, began with several hors d'oeuvres: tomatoes with crabmeat in a remoulade sauce, individual bacon and onion quiches, shrimp paste on toast rounds and pineapple with yogurt dip.

For dinner she served a cream of carrot soup, using Idaho trout served cold with dill sauce. Then came veal medallions with artichoke hearts and mushroom sauce, baked stuffed Idaho potatoes and the sugar snap peas. They were steamed and then dressed with a little butter and salt. A Boston lettuce salad had hearts of palm and cashews in a garlic dressing. Dessert was raspberry macaroon mousse.

Here are three of the recipes:

TROUT IN DILL SAUCE (8 servings) 8 trout, with heads and tails intact 1 medium carrot 1 medium onion 2 stalks celery, sliced 5 parsley sprigs 1 small bay leaf Pinch thyme Juice of 1 lemon 2 cups dry white wine 2 cup water Fish heads and trimmings

Combine all ingredients except the trout and simmer until vegetables are soft. Strain through several layers of cheesecloth and chill before poaching fish.

Fillet fish and place fish fillets in bottom of shallow baking dish. Pour bouillon over just to cover and place over moderate heat, bringing liquid just to simmering point. Place dish in 350-degree oven and bake until fish flakes easily, about 10 minutes. Cool fish completely in bouillon; remove and flake. Shape flaked fish into servingsize mounds and place on bed of lettuce. Serve with dill sauce.

DILL SAUCE 2 egg yolks 4 tablespoons heavy cream 1/2 cup vinaigrette* 1 teaspoon lemon juice, or to taste 1/4 teaspoon minced fresh dill

Beat yolks and cream in bowl until thorougly blended. Then beat in vinaigrette in a stream of droplets, as if making mayonnaise. Season to taste with lemon juice; stir in dill. Chill.

*To make vinaigrette: Beat 3/4 cup oil with 1/4 cup tarragon vinegar and 1/4 teaspoon dry mustard.

CREAM OF CARROT SOUP (8 servings) 1 pound young carrots 4 cups chicken stock or broth 3 cloves garlic 1/2 cup heavy cream Salt and pepper to taste 1/4 teaspoon nutmeg 1 teaspoon turmeric Chopped parsley for garnish

(If you can get very young carrots, use a little of the tops, chopped up, in the soup.) Slice carrots 1/2 inch thick. Place in large saucepan with chicken stock and bring to boil. Reduce heat and simmer 20 minutes; cool. Add garlic and process with steel blade in food processor or puree in blender. Reheat Stir 1 cup of warm soup into cream and combine with remaining soup. Bring to simmering point. Do not boil or soup may curdle. Season to taste with salt and pepper, nutmeg and turmeric. Serve sprinkled with parsley.