- Preheat oven to 400°F. Lightly coat 4 (8-ounce) ramekins or oven-safe baking dishes with nonstick spray. Cut 4-inch circle from each slice bread and firmly press 1 into bottom of each ramekin; set aside. Discard scraps or save for another use.
- 3 Whisk together eggs, egg whites, remaining 1/4 teaspoon salt, and pepper in medium bowl until frothy; stir in cooked vegetables and 1/4 cup cheese blend. Divide mixture evenly among ramekins. Sprinkle each with 1 tablespoon remaining cheese.
- 4 Place ramekins on small baking sheet and bake until tip of knife inserted into center of each casserole comes out clean, about 20 minutes. Remove from oven and cool 5–10 minutes before serving.
- 2 Heat oil in medium skillet over medium-high heat. Add onion, bell pepper, zucchini, jalapeño, and 1/4 teaspoon salt; cook, stirring occasionally, until vegetables soften, about 5 minutes. Remove from heat and set aside.
- Serving size: (1 casserole)
You can make the casseroles ahead, cool them completely, cover each with plastic wrap, and refrigerate up to 3 days. Reheat in the microwave on High until hot, 1 to 1½ minutes