My grandma's secret recipe that everybody couldn't stop eating! Easy and hearty dinner

Ingredients:
2-3 sausages
1/2 tbsp olive oil
1 onion
2 garlic cloves
1 can of white beans
700g crushed tomatoes (28 oz.)
basil leaves
chili flakes (optional)
2-3 eggs
cheese (optional)
parsley (optional)