Cook pasta according to package instructions. Drain well and set aside.
Heat a large pan over medium/high heat. Add the margarine and allow it to melt. Bring to a slight simmer then add the minced onion and garlic. Allow the garlic and onion to cook in the margarine for about 5 minutes. Do not let the margarine burn but allow it to get a really nice golden brown color
Stir the flour into the onions. Cook for another 2-3 minutes, until golden. Slowly pour in the milk while stirring constantly.
Add in all the spinach and stir together until it’s wilted down. Stir in the cheeses and allow it to melt. Add in the pasta and toss to coat.
Add the seasonings (to taste) and toss to coat