Pan Seared Tuna with Tortellini and Citrus Basil Pesto

2 tuna fillets (or salmon as an alternative)
2 garlic cloves
½ cup freshly grated parmesan cheese
½ cup nuts of your choice: walnut, pine nut, pistachio or almond
1 tablespoon orange zest, grated
2-3 tablespoons freshly squeezed orange juice
1 teaspoon lemon zest, grated
1 teaspoon freshly squeezed lemon juice
½ teaspoon each salt, pepper and crushed red pepper (if desired)
6-8 tablespoons extra virgin olive oil
8-10 leaves fresh basil, thinly sliced

INSTRUCTIONS
Cook pasta according to directions in a pot of salted boiling water.
Heat a large heavy bottom skillet over medium to high heat.
Coat both sides of tuna fillets with a drizzle of olive oil, salt and pepper.
Meanwhile, process all the ingredients except basil and oil in a food processor or blender.
Add oil; process for 30 seconds.
Remove from food processor and stir in fresh basil leaves.
Place tuna fillets into hot pan searing/cooking for 3 minutes per side.
Remove from pan and top each fillet with 2 tablespoons of the citrus basil pesto.
Drain pasta reserving 1/2 cup of cooking liquid.
Toss tortellini with pesto and basil adding a little of the cooking liquid to thin the sauce out if it is too thick.
Add more cheese if desired.
Serve tortellini with tuna fillets.