THE WORD went out that Chicago's Pump Room has a marvelous vegetable terrine with layers of paper-thin vegetables and an undefinable seasoning. Almost as quickly as you can say terrine de legumes, I was shaking hands with chef Gabino Sotelino.

Vegetable terrines are becoming more popular, but generally they consist of layers of cooked pureed vegetables resulting in a mousse-like texture.

Sotelino's creation features sliced vegetables that still retain some crispness. There's no cream, butter or eggs, so the dish is extremely light, refreshing and relatively low in calories.

Each ribbon-like strip of vegetables contributes a distinctive flavor to the dish.

"I believe modern cooking has to be imaginative, I don't want to copy others' cooking," said Sotelino, a Spaniard. "Coming up with new vegetable dishes is part of my love of cooking."

His training provided him with respect for ingredients. No shortcuts are allowed when Sotelino cooks. For example, the terrine requires a jellied consomme. It can be prepared from scratch by simmering veal bones and vegetables for hours, skimming frequently, then boiling down the liquid and flavoring with a little vermouth or sherry. Or you can open a can and pour in the liquor, a five-minute process.

"You can use canned consomme if you want a canned taste. I don't. It depends on how far you want to go," said Sotelino. That indescribable accent in the terrine is duck fat. One could use butter or chicken fat, but it wouldn't be the same as the Pump Room's recipe. There is plenty of leeway in the recipe, however. Any vegetable combination can be used as long as it provides a contrast in colors. The terrine could also be prepared in a decorative mold and placed on the table whole.

To save last-minute aggravation, prepare all the vegetables and the consomme before beginning to assemble the terrine. The vegetables should be tepid or cold and the consomme chilled and syrupy. Make the dish in the morning for serving that evening. TERRINE DE ELGUMES 8 to 13 ounces jellied consomme with a little dry vermouth added 1 large eggplant Salt and pepper 3 zucchini 1 large white onion, peeled 1 large carrot 2 red peppers 8 ounces clarified duck fat 2 large tomatoes 1 1/2 tablespoons chopped fresh chives

Pour enough consomme into a 9-inch loaf pan to form a 1/2-inch layer on the bottom. Place in refrigerator to solidify.

Wash and dry all vegetables. Slice eggplant about 1/2-inch thick. Salt well and set aside on platter to get rid of bitter liquid. Slice zucchini and onions paper-thin. Trim end off carrot, pare and cut into long, very thin slices.

Place peppers on sheet in 375-degree oven and roast 15 minutes until skin just blisters. Peel skin off peppers; remove tops and seeds. Cut into thick strips, season with salt and pepper and set aside.

Blanch carrot strips, rinse in cold water. Season with salt and pepper and set aside.

Put duck fat in skillet. Rinse eggplant of salt and pat dry. Lightly saute eggplant; drain on paper towels; season. Peel off skin on edge of eggplant and set eggplant aside. Saute zucchini and onions separately, season and set aside.

Dip tomatoes into boiling water until skins split. Peel, core and seed. Slice and set aside.

To assemble, place a layer of eggplant over consomme, completely covering it. Add a layer of zucchini, a layer of peppers, a layer of onions, a layer of carrots, another eggplant layer, another zucchini layer (another onion layer if there are leftovers) and a tomato layer. Season tomate layer with salt and white pepper. Sprinkle chives on top. Pour remaining gelatin over, making sure it seeps into all layers. Refrigerate for 8 hours.

Serve as appetizer with a creamy mustard vinaigrette, some fresh watercress or watercress salad.

Note: Unless you're cooking a duck it's practically impossible to get duck fat. The vegetables may be sauteed in butter instead.