Penne with Creamy Spinach Tomato Sauce

1/2 lb whole wheat penne
olive oil
1 small onion, chopped
2 garlic cloves, pressed
2 cups spinach leaves
1 cup fat free ricotta cheese
1/2 cup hot water
1 cup small diced tomatoes (canned or fresh)
spices - basil, oregano, salt, pepper
parmesean cheese

Boil water and cook pasta. Saute onion and garlic for 5 minutes then add spinach and cook until wilted. Meanwhile, blend ricotta and hot water until smooth. Add to spinach mixture and use a hand blender to puree the spinach and cheese mixture in the pot until creamy. Add tomatoes and then spices and parmesean cheese to taste. Drain penne and mix with sauce. Top with additional cheese. Enjoy.