|Sliced mushrooms||1 Cup (16 tbs)|
|Chopped onion||1⁄2 Cup (8 tbs)|
|Chopped red bell pepper||1⁄2 Cup (8 tbs)|
|Chopped zucchini||1⁄2 Cup (8 tbs)|
|Chopped yellow squash||1⁄2 Cup (8 tbs)|
|Plum tomatoes||2 Large, coarsely chopped|
|Low sodium tomato sauce||2 Cup (32 tbs)|
|Dried red pepper flakes||1⁄4 Teaspoon|
|Cooked pasta shells||4 Cup (64 tbs), hot|
|Part skim ricotta cheese||1 Cup (16 tbs)|
1. To prepare sauce, spray medium nonstick skillet with nonstick cooking spray. Add mushrooms, onion, bell pepper, zucchini, yellow squash, and tomatoes. Cook over medium-high heat until onion is translucent, stirring occasionally, 5 minutes. Stir in tomato sauce and red pepper flakes; reduce heat to low; simmer 10 minutes.
2. Place 1 cup pasta in each of 4 serving bowls; ladle sauce mixture evenly over each. Spoon 1/4 cup ricotta in center of each serving.