Liberally season ground beef with black pepper, seasoning salt and a few dashes of Italian seasoning. Mix mushrooms, green pepper, onion with beef, cover and cook till veggies are tender. Drain. Add pasta sauce, red pepper, brown sugar, chili powder. Lower heat to a simmer and cover.
Next boil lasagna noodles in salted water till al-dente. Drain and rinse with cool water.
Create an assembly area with sauce, noodles, cheeses. Turn oven to 350 degrees to preheat while assembling.
Begin with a thin layer of sauce on bottom of pan then layer of noodles. Usually three noodles will cover a 9x13 pan. Repeat sauce, sprinkle with feta then shredded cheese then noodles, repeat.
You will have to eyeball your ingredients to make the ratio work out evenly. Basically you are using 4 layers of sauce and three layers of cheeses & noodles. Your last layer should be shredded cheese & you can sprinkle a little Italian seasoning on top if you like for decoration.
This recipe completely fills a regular 9x13 pan. Obviously if you have an extra deep lasagna pan that can hold more layers of noodles that would be fabulous, just use less filling between the noodle layers.
I like the contrast in taste of the feta and the sweet/spicy sauce. If you don't like the taste of feta, I've used cottage cheese before, but I like to wrap it in cheese cloth & squeeze out a lot of the moisture first. Otherwise you end up with soupy lasagna.