1 jar (12 oz) roasted red pepper, drained, sliced and cleaned
Heat oven to 350F. Oil the bottom and sides of a 9-inch springform pan. Peel the sweet potato and slice crosswise into 1/4-inch-thick rounds. Arrange the sweet potato in overlapping layers in bottom of pan, sprinkling lightly with salt and pepper. Cover pan with foil and bake 20 minutes.
Meanwhile, heat the oil in a skillet and sautee onion until tender; set aside. Drain the spinach and squeeze in a colander to remove excess liquid. Combine spinach, 1 cup cheese, salt and pepper to taste and mix well; set aside.
Uncover pan and spread spinach mixture evenly on top of sweet potato layer; sprinkle with 1/4 cup pecans. Slice the yellow squash crosswise into very thin (about 1/8-inch thick) rounds and layer in pan alternating with the onion. Top with 1/4 cup each pecans and cheese, the basil, salt and pepper. Arrange red pepper pieces in a single layer on top.
Place pan on a rimmed baking sheet and press down on torte with the back of a metal spatula to squeeze out any remaining excess liquid. Drain the liquid, brush the red pepper layer lightly with oil and bake torte on top of baking sheet 20 minutes. Sprinkle torte with remaining 1/4 cup cheese and pecans and bake 6 to 8 minutes longer or until cheese melts and pecans are lightly toasted. Cool at least 15 minutes. To serve, run a thin knife around the inside edge of pan to loosen torte. Remove sides of pan and cut into wedges to serve.