Preheat oven to 425 degrees Fahrenheit
Slice Zucchini in lengthwise in thin 1/4 inch slices. Slice Red Bell Pepper into thin rings. Coat vegetables in olive oil, salt, and pepper. Place on a baking sheet and roast for 20 minutes.
While the vegetables are roasting, start the sauce.
Saute onions and garlic in 1 Tbsp olive oil on medium heat until onions are translucent. Add Tomato paste, stir and cook for another 1-2 minutes. Add crushed tomatoes, spices, salt, and pepper. Simmer on low for 20 minutes stirring occasionally.
Vegetables will likely be finished 10 minutes before the sauce. Remove vegetables and set aside to cool.
Add spinach to the sauce. Fold into the tomato sauce and cook for another few minutes until spinach is soft and cooked
Reduce oven temperature to 325 degrees
In a glass rectangle dish, add a thin layer of sauce to the bottom of the dish to prevent sticking. Start layering. Start with green lentil pasta, add layer of zucchini opposite direction of pasta, layer of cheese. Add another layer of sauce.This time add the Red Bell Pepper followed by Mozarella cheese. Repeat Zucchini layer. Leave enough sauce and cheese for the very top. Cheese should be your last layer.
Cook uncovered for 20 minutes or until cheese looks fully melted and lasagna appears cooked through.
Remove from oven and let rest for 10 minutes